International Recommendations for Energy Statistics (IRES) · 2017. 10. 6. · Energy Statistics (IRES) United Nations. New York, 2016 [final edited version prior to typesetting]

ST/ESA/STAT/SER.M/93

Department of Economic and Social Affairs Statistics Division

Statistical Papers Series M No. 93

International Recommendations for Energy Statistics (IRES)

United Nations. New York, 2016

[final edited version prior to typesetting]

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ST/ESA/STAT/SER.M/93

UNITED NATIONS PUBLICATION

Sales No. E.14.XVII.11

ISBN: 978-92-1-161584-5

eISBN: 978-92-1-056520-2

Copyright © United Nations, 2016

All rights reserved

iii

Preface

The International Recommendations for Energy Statistics (IRES) provide a comprehensive

methodological framework for the collection, compilation and dissemination of energy statistics in

all countries irrespective of the level of development of their statistical system. In particular, IRES

provides of a set of internationally agreed recommendations covering all aspects of the statistical

production process, from the institutional and legal framework, basic concepts, definitions and

classifications to data sources, data compilation strategies, energy balances, data quality issues and

statistical dissemination.

IRES was prepared in response to the request of the United Nations Statistical Commission, at its

thirty-seventh session (7-10 March 2006), to review the United Nations manuals on energy

statistics, develop energy statistics as part of official statistics, harmonize energy definitions and

compilation methodologies and develop international standards in energy statistics.

The preparation of IRES was carried out by the United Nations Statistics Division (UNSD) in close

cooperation with the Oslo Group on Energy Statistics and the Intersecretariat Working Group on

Energy Statistics (InterEnerStat).

A major milestone of IRES is the Standard International Energy Product Classification (SIEC),

which is the first standard classification for energy products. It has been built on a set of

internationally harmonized definitions of energy products developed by InterEnerStat as mandated

by the United Nations Statistical Commission. The adoption of SIEC as an international standard

classification for energy products represents a significant step forward for energy statistics at the

international level. SIEC not only provides a unified set of product definitions, but also uses a

standard coding scheme and a common hierarchy of categories, and provides links to other

internationally agreed product classifications, such as the Central Product Classification (CPC) and

the Harmonized Commodity Description and Coding System (HS). In addition to its use within

traditional forms of energy statistics, such as energy balances, SIEC may also serve in frameworks

that aim to combine energy statistics with other statistical domains, such as energy accounts used

within the field of environmental-economic accounting.

The present document has undergone an extensive preparation process that included consultations

with experts, two rounds of worldwide consultation and a final review by the Expert Group on

Energy Statistics. The United Nations Statistical Commission, at its forty-second session (22-25

February 2011), adopted IRES as a statistical standard and encouraged its implementation in

countries. The Commission also supported the work of UNSD on the Energy Statistics Compilers

Manual to provide additional practical guidelines in the collection and compilation of energy

statistics.

iv

v

Acknowledgements

The International Recommendations for Energy Statistics have been prepared by the United

Nations Statistics Division (UNSD) in close collaboration with the Oslo Group on Energy

Statistics and the Intersecretariat Working Group on Energy Statistics (InterEnerStat). The process

involved also other experts who provided advice on specific topics, countries and

international/regional organizations participating through two rounds of global consultation and the

participants of the Expert Group on Energy Statistics who reviewed the document prior to its

submission to the Statistical Commission.

Members of the Oslo Group on Energy Statistics who contributed to the drafting and review of the

document include: Mr. G. Brown (Australia), Mr. W. Bitterman (Austria), Mr. Y. Yusifov

(Azerbaijan), Mr. J. Lacroix (Canada), Mr. A. Kohut (Canada), Mr. A. A. Zamaghi (Denmark),

Mr. T. Olsen (Denmark), Mr. P.K. Ray (India), Ms. G. S. Rathore (India), Mr. M. Howley

(Ireland), Mr. C. R. López-Pérez (Mexico), Mr. H. Pouwelse (Netherlands), Mr. A. Tostensen

(Norway), Ms. K. Kolshus (Norway), Mr. O. Ljones (Norway), Ms. J. E. W. Toutain (Norway),

Mr. S. Peryt (Poland), Mr. A. Goncharov (Russia), Mr. J. Subramoney (South Africa), Mr. P.

Westin (Sweden), Mr. I. MacLeay (United Kingdom), Mr. P. Kilcoyne (United States), Mr. A.

Gritsevskyi (International Atomic Energy Agency), Mr. J. Y. Garnier (International Energy

Agency), Ms. K. Treanton (International Energy Agency), Mr. P. Loesoenen (Eurostat) and Mr. R.

Mertens (Eurostat).

UNSD is grateful to Mr. Ljones and Mr. Garnier for leading the Oslo Group and the Intersecretriat

Working Group on Energy Statistics, respectively, and their contribution to the preparation of

IRES.

The preparation of IRES was undertaken under the supervision and guidance of Mr. V. Markhonko

(UNSD) and concluded under the overall supervision of Mr. R. Becker (UNSD). Mr. Markhonko,

Ms. I. Di Matteo, Mr. L. Souza, Mr. O. Andersen, Mr. A. Blackburn, and Mr. Becker were

involved in the drafting of the text at various stages of the drafting process.

vi

Contents

Preface ...............................................................................................................................................iii

Acknowledgements ............................................................................................................................. v

Contents ............................................................................................................................................. vi

List of Abbreviations and Acronyms .................................................................................................. x

Chapter 1. Introduction ................................................................................................................. 1

A. Background ............................................................................................................................. 2

B. Purpose of the international recommendations for energy statistics ...................................... 4

C. Users and uses of energy statistics .......................................................................................... 9

D. IRES development process ................................................................................................... 10

E. Structure of IRES .................................................................................................................. 11

F. Summary of recommendations ............................................................................................. 13

G. Implementation and revision policy ...................................................................................... 20

Chapter 2. Scope of energy statistics .......................................................................................... 21

A. Energy and energy statistics .................................................................................................. 21

B. Basic concepts and boundary issues: an overview ............................................................... 23

Chapter 3. Standard International Energy Product Classification .............................................. 26

A. Introduction ........................................................................................................................... 26

B. Purpose and scope of the SIEC ............................................................................................. 27

C. Classification criteria and coding system ............................................................................. 28

D. Definitions of energy products .............................................................................................. 34

Chapter 4. Measurement units and conversion factors ............................................................... 51

A. Introduction ........................................................................................................................... 51

B. Measurement units ................................................................................................................ 51

1. Original units .................................................................................................................... 53

2. Common units ................................................................................................................... 56

C. Calorific values ..................................................................................................................... 56

1. Gross and net calorific/heating values .............................................................................. 57

2. Default vs. specific calorific values .................................................................................. 58

3. How to calculate average calorific values ........................................................................ 59

4. Default calorific values ..................................................................................................... 60

5. Units recommended for dissemination ............................................................................. 66

Chapter 5. Energy Flows ............................................................................................................ 68

A. Introduction ........................................................................................................................... 68

B. Concept of energy flows ....................................................................................................... 68

C. Definition of main energy flows ........................................................................................... 69

D. Energy industries .................................................................................................................. 73

vii

1. Electricity and heat ........................................................................................................... 76

2. Transformation processes ................................................................................................. 79

E. Other energy producers ........................................................................................................ 81

F. Energy consumers and energy uses ...................................................................................... 81

1. Energy consumers ............................................................................................................ 82

2. Cross classification of uses and users of energy .............................................................. 83

Chapter 6. Statistical Units and Data Items ................................................................................ 87

A. Introduction .......................................................................................................................... 87

B. Statistical units ..................................................................................................................... 87

1. Statistical units and their definitions ................................................................................ 87

2. An illustrative example .................................................................................................... 90

3. Statistical units for energy statistics ................................................................................. 92

C. Reference list of data items .................................................................................................. 92

1. Characteristics of statistical units ..................................................................................... 92

2. Data items on energy flows and stock levels ................................................................... 96

3. Data items on production, storage and transmission capacity ....................................... 100

4. Data items for assessment of economic performance .................................................... 102

5. Data items on mineral and energy resources .................................................................. 105

Chapter 7. Data collection and compilation ............................................................................. 107

A. Legal framework ................................................................................................................ 107

B. Institutional arrangements .................................................................................................. 108

C. Data collection strategies ................................................................................................... 110

1. Scope and coverage of data collection ........................................................................... 110

2. Organization of data collection ...................................................................................... 114

D. Data Sources ....................................................................................................................... 115

1. Statistical data sources ................................................................................................... 115

2. Administrative data sources ........................................................................................... 119

E. Data compilation methods .................................................................................................. 120

Chapter 8. Energy balances ...................................................................................................... 123

A. Introduction ........................................................................................................................ 123

B. Scope and general principles of energy balance compilation ............................................ 124

C. Structure of energy balance: an overview .......................................................................... 126

1. Top block - Energy supply ............................................................................................. 127

2. The middle block ............................................................................................................ 129

3. The bottom block - Final consumption .......................................................................... 130

4. Statistical difference ....................................................................................................... 133

D. Templates of detailed and aggregated energy balances ..................................................... 134

E. Data reconciliation and estimation of missing data ........................................................... 136

F. Commodity balances .......................................................................................................... 137

Chapter 9. Data Quality Assurance and Metadata ................................................................... 140

A. Introduction ........................................................................................................................ 140

B. Data quality, quality assurance and quality assurance frameworks ................................... 140

1. Data quality .................................................................................................................... 140

2. Quality assurance ........................................................................................................... 140

3. Data quality assurance frameworks................................................................................ 141

viii

4. Objectives, uses and benefits of quality assurance frameworks ..................................... 143

5. Dimensions of quality ..................................................................................................... 144

6. Interconnectedness and trade-offs ................................................................................... 147

C. Measuring and reporting on the quality of statistical outputs ............................................. 147

1. Quality measures and indicators ..................................................................................... 147

2. Examples and selection of quality measures and indicators ........................................... 148

3. Quality reports ................................................................................................................ 151

4. Quality reviews ............................................................................................................... 152

D. Metadata on energy statistics .............................................................................................. 153

Chapter 10. Dissemination ......................................................................................................... 157

A. Importance of energy statistics dissemination .................................................................... 157

B. Data dissemination and statistical confidentiality ............................................................... 158

C. Reference period and dissemination timetable ................................................................... 160

D. Data revision ....................................................................................................................... 162

E. Dissemination formats ........................................................................................................ 163

F. International reporting ........................................................................................................ 163

Chapter 11. Uses of Basic Energy Statistics and Balances ........................................................ 165

A. Introduction ......................................................................................................................... 165

B. The System of Environmental-Economic Accounting for Energy ..................................... 165

1. Main differences between energy balances and energy accounts ................................... 166

2. Adjustments for the compilation of energy accounts ..................................................... 169

C. Energy indicators ................................................................................................................ 170

D. Greenhouse gas emissions .................................................................................................. 173

1. Climate change and greenhouse emissions ..................................................................... 173

2. IPCC guidelines for estimating GHG emissions ............................................................ 174

3. Energy emissions and energy statistics ........................................................................... 176

Annex A. Primary and Secondary products; Renewables and non-renewables.......................... 178

Annex B. Additional tables on conversion factors, calorific values and measurement units ..... 181

References ....................................................................................................................................... 184

List of tables

Table 1.1 Summary of the main recommendations and encouragements contained in IRES .................. 14

Table 3.1: Standard International Energy Product Classification (SIEC) ............................................... 31

Table 4.1: Default net calorific values for energy products ..................................................................... 60

Table 4.2: Influence of moisture content on net calorific values of standard fuelwood .......................... 63

Table 4.3: Conversion table for fuelwood ............................................................................................... 64

Table 4.4: Recommended units for dissemination ................................................................................... 66

Table 5.1: Energy industries with reference to the relevant ISIC category ............................................. 74

Table 5.2: Main activity producers and autoproducers of electricity and heat ........................................ 77

Table 5.3: Main categories of energy consumers .................................................................................... 82

Table 5.4: Mode of transport ................................................................................................................... 85

Table 6.1: Mineral and energy resources relevant for energy ................................................................ 105

Table 6.2: Categorization of mineral and energy resources relevant for energy ................................... 105

Table 11.1: Energy Indicators linked to the social dimension ............................................................... 171

ix

Table 11.2: Energy Indicators linked to the economic dimension ......................................................... 171

Table 11.3: Energy Indicators linked to the environmental dimension ................................................. 172

List of Boxes

Box 1.1: The UN Fundamental Principles of Official Statistics ................................................................ 6

Box 4.1: International System of Units ................................................................................................... 52

Box 5.1: Principal, secondary and ancillary activities ............................................................................ 73

Box 9.1: Template for a Generic National Quality Assurance Framework ........................................... 142

Box 9.2: Selected Indicators for Measuring the Quality of Energy Statistics ....................................... 149

Box 9.3: Metadata Items for Statistical Releases .................................................................................. 154

Box 11.1: Methods for the estimation of GHG emissions from fossil fuel combustion ........................ 175

List of Figures

Figure 5.1: Diagram of the main energy flows ........................................................................................ 69

Figure 5.2: Cross classification of uses and users of energy ................................................................... 84

Figure 6.1: Example of a large oil corporation ........................................................................................ 90

x

List of Abbreviations and Acronyms

API American Petroleum Institute

BPM6 Balance of Payments and International Investment Position Manual

Btu British thermal unit

CHP Combined Heat and Power

CPC Central Product Classification

DQAF Data Quality Assessment Framework

EEA European Environmental Agency

ESCM Energy Statistics Compilers Manual

Eurostat Statistical Office of the European Communities

GCV Gross Calorific Value

GDP Gross Domestic Product

GHG Greenhouse Gas

GTL Gas-to-Liquids

GWh Gigawatt hour

HS Harmonized Commodity Description and Coding System

IEA International Energy Agency

InterEnerStat Intersecretariat Working Group on Energy Statistics

IPCC Intergovernmental Panel on Climate Change

IRES International Recommendations for Energy Statistics

ISIC International Standard Industrial Classification of All Economic Activities

LNG Liquefied Natural Gas

LPG Liquefied Petroleum Gas

kWh Kilowatt hour

NQAF National Quality Assurance Framework

NCV Net Calorific Value

NGL Natural Gas Liquid

xi

OECD Organisation for Economic Co-operation and Development

SBP Special Boiling Point

SDMX Statistical Data and Metadata Exchange

SEEA System of Environmental-Economic Accounting

SEEA-Energy System of Environmental-Economic Accounting for Energy

SI Systèmes International d’Unités

SIEC Standard International Energy Product Classification

SIMS Single Integrated Metadata Structure

SNA System of National Accounts

TES Total Energy Supply

Tce Ton of coal equivalent

Toe Ton of oil equivalent

UN United Nations

UNFC United Nations Framework Classification for Fossil Energy and Mineral

Reserves and Resources

UNFCCC United Nations Framework Convention on Climate Change

UNSD United Nations Statistics Division

VAT Value added tax

1

Chapter 1. Introduction

1.1 Energy is fundamental for socio-economic development. The availability of and access to

energy and energy sources are particularly essential to poverty reduction and further improvements

in standards of living.1 However, at the same time, with the constantly increasing demand for

energy, there are growing concerns about the sustainability and reliability of current production

and consumption patterns and the impact of the use of fossil fuel on the environment.

1.2 Under these circumstances reliable and timely monitoring of the supply and use of energy

becomes indispensable for sound decision making. However, such monitoring is possible only if

high quality energy statistics are systematically compiled and effectively disseminated. This, in

turn, requires the availability of internationally agreed standards and other necessary guidance to

ensure cross-country data comparability and the existence of adequate mechanisms for data

dissemination to policy makers, both at national and international level, as well as to society in

general. In this context, an overarching goal of the International Recommendations for Energy

Statistics (IRES) is to provide such standards and guidance to national compilers covering relevant

concepts and definitions, classifications, data sources, data compilation methods, institutional

arrangements, data quality assurance, metadata and dissemination policies.

1.3 The target audience. IRES is a multipurpose document intended to address the needs of

various user groups. Its target audience, which is quite diverse, comprises:

a. Compilers of national energy statistics, irrespective of whether they are located in

national statistical offices, energy ministries (agencies), other governmental institutions

or other agencies, and who, by the application of the provided recommendations, can

collectively strengthen national programmes of energy statistics as an integral part of

official statistics and produce data that meet the challenges of our time;

b. Compilers of other statistics who will have in IRES an authoritative source of

information on internationally agreed standards with respect to energy statistics and on

which basis the cooperation with energy statisticians should be pursued in order to

improve the overall quality of official statistics;

c. Policy makers whom IRES will help to better assess the strategic importance of energy

statistics, the complexity of the issues energy statistics face and to appreciate the need

for allocation of the necessary resources for producing such statistics;

1 See, for example, Johannesburg Plan of Implementation (JPOI), paragraph 9(g). Available at

http://www.un.org/esa/sustdev/documents/WSSD_POI_PD/English/WSSD_PlanImpl.pdf.

2

d. International and regional organizations dealing with energy-related issues which will

appreciate IRES as the reference document of global importance on which they can

base their work;

e. Research institutions and energy analysts which might use IRES to better assess the

quality of available data and provide valuable feedback to energy statistics compilers;

and;

f. The general public, which will find in IRES a wealth of information essential for better

understanding energy statistics and for formulating sound judgements regarding various

energy policy issues.

A. Background

1.4 Due to the critical role energy plays in socio-economic development, the availability of

high-quality energy statistics has always been a matter of concern for the statistical community.

The United Nations Statistical Commission has discussed issues relevant to energy statistics as part

of economic statistics since its inception. In the aftermath of the energy crisis of the early 1970s,

the Commission put energy statistics on its agenda as a separate item and requested a special report

on energy statistics to be prepared and presented to it for discussion.

1.5 Accordingly, the report of the United Nations Secretary-General was prepared and

submitted to the Commission at its nineteenth session in 1976.

2 The Commission welcomed the

report and agreed that the development of a system of integrated energy statistics should have high

priority in the Commission's programme of work. It agreed on the use of energy balances as the

key instrument in the coordination of work on energy statistics and the provision of data in a

suitable form for understanding and analysing the role of energy in the economy. The Commission

also recommended the preparation of a standard international classification for energy statistics as

part of the global system of integrated energy statistics and considered such a classification as an

essential element for the further development and harmonization of energy statistics at the

international level.

1.6 Following the Commission’s recommendations, the United Nations Statistics Division

(UNSD) prepared a detailed report on basic concepts and methods relevant to energy statistics. The

Commission, at its twentieth session in 1979, appreciated the report and decided that it should be

made available for circulation to national and international statistical offices, as well as to other

relevant agencies. In response to this decision, UNSD issued in 1982 the Concepts and methods in

energy statistics, with special reference to energy accounts and balances: a technical report.3 At

2 Towards a System of Integrated Energy Statistics. Report of the Secretary-General to the nineteenth session of the

Statistical Commission (E/CN.3/476), 15 March 1976.

3 Concepts and methods in energy statistics, with special reference to energy accounts and balances: a technical

report, Studies in Methods, Series F, No. 29, United Nations, New York, 1982.

3

its

twenty-fourth session in 1987, the Commission again discussed energy statistics and

recommended that a handbook on conversion factors and units of measurement for use in energy

statistics be published as well. Implementing this recommendation, UNSD issued later in 1987

another technical report entitled Energy statistics: definitions, units of measure and conversion

factors.4 These two documents have played a major role in the development of energy statistics

both at the national and international level.

1.7 As countries were gaining experience with the compilation of energy statistics and various

regions developed specific data needs, it became necessary to produce additional guidance. In

1991, UNSD published Energy statistics: a manual for developing countries,5 and in 2004 the

International Energy Agency (IEA) and the Statistical Office of the European Communities

(Eurostat) published their Energy Statistics Manual6 to assist member countries of the Organisation

for Economic Co-operation and Development (OECD) and the European Union (EU) in compiling

their joint energy statistics questionnaire and to provide related guidance. Both manuals were

welcome complements to the earlier United Nations publications. The OECD/IEA/Eurostat manual

contains the most recent background information and clarifications of some difficult conceptual

issues.

1.8 In view of mounting evidence that energy statistics still have serious shortcomings in terms

of data availability and international comparability, the Commission at its thirty-sixth session in

2005 undertook a programme review based on a report prepared by Statistics Norway (see

E/CN.3/2005/3). The Commission, during its deliberations, recognized the need for developing

energy statistics as part of official statistics and for revising the existing recommendations for

energy statistics.

1.9 As part of the follow-up actions to the Commission’s decisions, UNSD convened an ad hoc

expert group on energy statistics (New York, 23-25 May 2005), which recommended that further

work on energy statistics should be carried out by two complementary working groups—a city

group and an inter-secretariat working group. The city group’s task was to contribute to the

development of improved methods and international standards for national official energy

statistics, and the inter-secretariat working group was requested to enhance inter-agency

coordination, particularly in the harmonization of the definitions of energy products. The detailed

terms of reference of both groups were approved by the Commission’s Bureau.7

4 Energy statistics: definitions, units of measure and conversion factors, Studies in Methods, Series F, No. 44, United

Nations, New York, 1987.

5 Energy statistics: a manual for developing countries, Studies in Methods, Series F, No. 56, United Nations, New

York, 1991.

6 Energy Statistics Manual, OECD/IEA/EUROSTAT, Paris, 2004.

7 See Report of the Secretary-General on Energy Statistics to the thirty-seventh session of the Commission,

E/CN.3/2006/10.

4

1.10 The Commission, at its thirty-seventh session in 2006, commended the progress made and

supported the establishment and mandate of the Oslo Group on Energy Statistics, convened by

Statistics Norway, and the Intersecretariat Working Group on Energy Statistics (InterEnerStat),

convened by IEA,8 and requested proper coordination mechanisms between them. The present

publication is the result of a close cooperation between UNSD, the Oslo Group on Energy

Statistics and InterEnerStat. While the Oslo Group on Energy Statistics concentrated on the

development of an overall conceptual framework for IRES, as well as data compilation and

dissemination strategies, InterEnerStat focused on the harmonization of definitions of energy

products and energy flows (See Chapters 3 and 5 for details.).

1.11 Parallel with IRES, the System of Environmental-Economic Accounting (SEEA), including

SEEA-Energy, was prepared. These forthcoming publications will provide guidance for

environmental and energy accounts consisting of agreed concepts, definitions, classifications and

inter-related tables and accounts. The SEEA-Energy accounting standards will be developed on the

basis of IRES (e.g., using data items provided in IRES, its classification of energy products and

definition of energy flows). Thus, IRES and SEEA-Energy are viewed as two complementary,

coordinated documents, and the relationship between them is further elaborated in Chapter 11.

1.12 The present document, adopted as a statistical standard by the Commission at its forty-

second session in February 2011, provides the internationally agreed standard for energy statistics.

B. Purpose of the international recommendations for energy statistics

1.13 The main purpose of IRES is to strengthen energy statistics as part of official statistics by

providing recommendations on concepts and definitions, classifications, data sources, data

compilation methods, institutional arrangements, approaches to data quality assessment, metadata

and dissemination policies. Developing energy statistics in compliance with IRES will make these

statistics more consistent with other fields of economic statistics, such as standard international

classifications of activities and products,9 as well as with the recommendations for other economic

statistics (e.g., the International Recommendations for Industrial Statistics, UN (2009b)).

1.14 In addition, IRES will serve as a reference document in support of the maintenance and

development of national energy statistics programmes. It will provide a common, yet flexible,

framework for the collection, compilation, analysis and dissemination of energy statistics that meet

the demands of the user community and are policy relevant, timely, reliable, and internationally

comparable. This framework can be utilized by all countries, irrespective of the level of

8 The IEA undertook an initiative to organize a group consisting of various regional and specialized agencies active in

energy statistics in 2004. Such a group, known as InterEnerStat, was established in 2005 and acts as the Intersecretariat

Working Group on Energy Statistics reporting to the Commission.

9 This includes the International Standard Industrial Classification of All Economic Activities (ISIC), the Central

Product Classification (CPC) and the Harmonized Commodity Description and Coding System (HS).

5

development of their statistical systems, as the basis for further improving existing energy statistics

programmes or establishing such programmes.

1.15 While all countries are expected to comply with IRES definitions and classifications to the

extent possible and practical, to follow the recommendations regarding data collection and

compilation, to maintain the highest possible data quality and to follow data dissemination

principles, they have flexibility in defining the scope of their own energy statistics programmes,

developing their data collection strategies and establishing appropriate institutional arrangements

that reflect country policy, circumstances, and resource availability.

1.16 Although there is no internationally accepted definition of the term official statistics, it is

widely used in the statistical community. In international practice, a particular body of statistics is

usually referred to as official statistics if it follows the United Nations Fundamental Principles of

Official Statistics10

(see Box 1.1) and is issued by an institution nationally or internationally

designated in this field. One of the key objectives of the Principles is to stress that high quality

must be an indispensable feature of official statistics. Quality of energy statistics is covered in

Chapter 9 and builds on the experience of countries and international organizations in this area.

10 The Fundamental Principles of Official Statistics were adopted at the Special Session of the United Nations

Statistical Commission, 11-15 April 1994. See Official Records of the Economic and Social Council, Special session,

Supplement No. 9 (E/CN.3/1994/18).

6

Box 1.1: The United Nations Fundamental Principles of Official Statistics11

Principle 1. Official statistics provide an indispensable element in the information system of a democratic society,

serving the Government, the economy and the public with data about the economic, demographic, social and

environmental situation. To this end, official statistics that meet the test of practical utility are to be compiled and

made available on an impartial basis by official statistical agencies to honor citizens' entitlement to public

information.

Principle 2. To retain trust in official statistics, the statistical agencies need to decide according to strictly

professional considerations, including scientific principles and professional ethics, on the methods and procedures

for the collection, processing, storage and presentation of statistical data.

Principle 3. To facilitate a correct interpretation of the data, the statistical agencies are to present information

according to scientific standards on the sources, methods and procedures of the statistics.

Principle 4. The statistical agencies are entitled to comment on erroneous interpretation and misuse of statistics.

Principle 5. Data for statistical purposes may be drawn from all types of sources, be they statistical surveys or

administrative records. Statistical agencies are to choose the source with regard to quality, timeliness, costs and

the burden on respondents.

Principle 6. Individual data collected by statistical agencies for statistical compilation, whether they refer to

natural or legal persons, are to be strictly confidential and used exclusively for statistical purposes.

Principle 7. The laws, regulations and measures under which the statistical systems operate are to be made public.

Principle 8. Coordination among statistical agencies within countries is essential to achieve consistency and

efficiency in the statistical system.

Principle 9. The use by statistical agencies in each country of international concepts, classifications and methods

promotes the consistency and efficiency of statistical systems at all official levels.

Principle 10. Bilateral and multilateral cooperation in statistics contributes to the improvement of systems of

official statistics in all countries.

1.17 Importance of developing energy statistics as official statistics. Energy is a necessary input

in all human activities and is critically important for socio-economic development. Therefore, it is

imperative that energy statistics of the highest quality possible are produced. To ensure that such

quality is attained, countries are encouraged to take steps to advance from the collection of

selected data items used primarily for internal purposes by various specialized energy agencies to

the establishment of an integrated system of multipurpose energy statistics as a part of their official

statistics in the context of the United Nations Fundamental Principles of Official Statistics and on

the basis of appropriate institutional arrangements. It is recognized that in many countries and

11 Although the original text of the United Nations Fundamental Principles of Official Statistics makes reference to

“official statistical agencies” only, in the context of energy statistics it should be understood to include national energy

agencies/institutions involved in the collection, compilation or dissemination of energy statistics.

7

regions such integrated systems have been established12

and efforts are being made to further

improve them, while a significant number of other countries are at the initial stages of this process.

1.18 Developing energy statistics as official statistics will be beneficial in a number of ways,

including: (i) strengthening the legal basis in order to guarantee confidentiality of data providers

and protection against data misuse; (ii) improving international comparability by promoting the

implementation of international standards and concepts; and (iii) fostering transparency in the

compilation and dissemination of statistics.

1.19 Actions to be taken to strengthen energy statistics as official statistics. Developing energy

statistics as part of countries’ official statistics is a long-term goal which requires careful planning

for development and implementation. Actions leading towards this goal should be taken both at the

international and national level.

1.20 At the international level, the strengthening of official energy statistics would be achieved

by developing the current international recommendations for energy statistics and carrying out the

respective implementation programmes. The implementation programme includes, for instance, the

preparation of the Energy Statistics Compilers Manual (ESCM) and other technical reports to

ensure sharing of good practices and improvements in data quality. It is recommended that

international organizations play an active role in IRES implementation and assist countries in

developing energy statistics work programmes as part of their national official statistics through,

for example, the preparation of training materials and organizing regular training programmes,

including regional workshops, and assisting countries in the sharing of expertise gained in this

process.

1.21 At the national level, further improvements in the legal framework and streamlining of the

institutional arrangements are needed. Certain issues, such as confidentiality, can be a challenge

since there may be strong tendencies towards market concentration and market liberalization on the

supply side for specific energy products, creating a conflict between the confidentiality

requirement and demand for data. Some guidance in this respect is provided in Chapters 7 and 10.

1.22 More efforts are required at the national level to raise the user confidence in energy

statistics, including making the processes of data compilation and dissemination fully transparent.

It is recommended that official energy statistics be treated as a public good and the agencies

responsible for their dissemination ensure that the public has convenient access to those statistics.

1.23 Specific needs addressed in the current version. The international recommendations for

energy statistics have not been reviewed as a whole since the 1980s and need to be revised and

updated to:

12 One of the most recent examples of such efforts is the adoption of the EU directive on energy statistics: Regulation

(EC) No 1099/2008 of the European Parliament and of the Council of 22 October 2008 on energy statistics.

8

(a) Take into account and provide recommendations on the statistical treatment of new

developments in energy production and consumption. Examples include the increased

complexity of energy markets (including their liberalization), the appearance of new

energy sources and technologies13

and the need for data to assess the sustainability and

efficiency of energy supply and consumption, which were not sufficiently taken into

account in the previous recommendations;

(b) Provide recommendations on topics not explicitly addressed in existing United Nations

publications, such as data compilation strategies, data quality, metadata and data

dissemination, as well as on the institutional arrangements needed for effective

compilation of official energy statistics;

(c) Provide definitions of data items recommended for collection, identify a range of

appropriate data sources and data compilation methods in order to assist countries in the

formulation of their data compilation strategies in the context of the increased

complexity of energy markets in rapidly globalizing economies and heightened

confidentiality concerns;

(d) Promote an integrated approach to energy statistics, in particular to improve

harmonization with other standard international classifications of activities and

products, as well as to take into account the new recommendations in related areas (e.g.,

in the International Recommendations for Industrial Statistics, 2008, the forthcoming

SEEA-Energy and the United Nations Framework Classification for Energy and

Mineral Resources);

(e) Recognize that, depending on a country’s circumstances, the responsibility for the

compilation and dissemination of official energy statistics may be vested in national

statistical offices, ministries of energy or other specialized agencies. Regardless of

where this responsibility lies, the agency contributing to official energy statistics should

be committed to adhering to the statistical standards of quality;

(f) Promote uniformity in the international reporting of energy data required for dealing

with global challenges such as sustainable development, energy security or climate

change, and for meeting other international needs, including improvement in coverage

and quality of the United Nations energy statistics database and energy databases of

other international and regional organizations.

13 For example, 40 years ago there was almost no electricity produced from nuclear energy; more recently wind and

solar energy have started to draw attention; biofuels have been quickly increasing in relevance and the future might see

the fast development of hydrogen and fuel cells. As a consequence, there is an obvious need for statistics and

statisticians to follow, if not to anticipate the fast evolution of the energy market.

9

C. Users and uses of energy statistics

1.24 Energy statistics are a specialized field of statistics whose scope has been evolving over

time and broadly covers (i) extraction, production, transformation, distribution, storage, trade and

final consumption of energy products and (ii) the main characteristics and activities of the energy

industries (see Chapter 2 for details). Energy statistics are seen as a multipurpose body of data.

Therefore, in the preparation of international recommendations for these statistics the needs of the

various user groups were taken into account. The main user groups and their needs are briefly

described below.

1.25 Energy policy makers. Policy makers use energy statistics for the formulation of energy

strategies and for monitoring their implementation. In this context, energy statistics are required,

inter alia, for the following:

(a) Formulation of energy policies and monitoring their impact on the economy. The

formulation of energy policies and the monitoring of their impact on the economy are

critically important for countries, as energy availability directly affects production,

imports, exports and investment which all have a significant impact on a country’s

economy. Detailed and high-quality energy statistics provide policy makers with the

information needed to make informed decisions and evaluate possible trade-offs. For

example, in the context of global price shocks in commodities, such as oil and gas,

policy makers may want to monitor the impact of national subsidy programmes for

those fuels. In other situations, policies on whether certain energy products can be

better used for food or used as fuel may be examined;

(b) Monitoring of national energy security. For the assessment of national energy security,

detailed statistics on energy supply, transformation, demand and stock levels are

indispensable. Data on production, trade, consumption, stock levels and stock changes

are politically sensitive as problems with energy supply may be perceived as a threat to

national independence, especially if national energy sources do not meet energy

demand;

(c) Planning of energy industries’ development and promotion of energy-conserving

technological processes. A basic prerequisite for such strategic planning is the

availability of systematic and detailed data covering the range of primary and secondary

energy products, as well as their flow from production to final consumption. This would

allow for assessment of the economic efficiency of various energy production processes

and energy consumption, and for building econometric models for forecasting and

planning future investments in the various energy industries and in energy conserving

technological processes;

(d) Environmental policy, especially greenhouse gas emission inventories, and

environmental statistics. There is a growing concern about the environmental effects

caused by emissions of greenhouse gases and other air pollutants from the use of

10

energy, especially from the use of fossil fuels. Enabling energy statistics to meet the

demand from environment statistics, especially concerning the emission of greenhouse

gases, must be one of the top priorities.

1.26 Business community. The availability of detailed energy statistics is critical for the business

community in general and for the energy industries in particular, for evaluating various business

options, assessing opportunities for new investments and analysing the energy market. Basic

energy statistics have to be relevant for those experts who follow the energy markets, as in many

countries changes in energy markets and energy prices will have a strong effect on the economic

situation.

1.27 Compilers and users of national accounts. In most systems of official statistics, national

accounts play a crucial role as they give the national picture of the economic situation and trends,

covering all production sectors, including energy, and all uses of goods and services. Basic

economic statistics, including energy statistics, are needed to meet the demands of the national

accounts.

1.28 Compilers of the System of Environmental-Economic Accounting for Energy (SEEA-

Energy). The SEEA-Energy expands the conventional national accounts to better describe the

extraction of energy from the environment, the use and supply of energy products within the

economy and the flows from the economy to the environment. Energy statistics are the basis for

the compilation of the SEEA-Energy, which organizes and integrates them in a common

framework together with economic statistics, thus providing additional information relevant to the

formulation and monitoring of energy policy.

1.29 International organizations. As international organizations were tasked with monitoring

global developments, including those related to energy and the environment, they need energy

statistics to carry out their activities. Therefore, international reporting obligations are an additional

important factor to be taken into account in developing energy statistics.

1.30 General public. The general public benefits from the availability of timely energy statistics

for evaluating the energy and environmental situation in order to make informed judgements about

the various options for energy policy. For example, information on energy consumption, its costs,

prices, and market trends will contribute to the public debate about efficiency, sustainability and

the economy.

D. IRES development process

1.31 The revision process included the preparation of an annotated outline of IRES for

worldwide consultation with countries and international organizations on its scope and content, the

holding of an International Workshop on Energy Statistics (Mexico, 2-5 December 2008) to

provide an opportunity for developing countries to express their concerns and discuss possible

solutions, the preparation of the draft recommendations and their review by the fourth and fifth

meetings of the Oslo Group, a worldwide consultation on the provisional draft of IRES, as well as

11

review and endorsement of the draft IRES by the second meeting of the United Nations Expert

Group on Energy Statistics (New York, 2-5 November 2010).

1.32 The Oslo Group, with Statistics Norway serving as its secretariat, and InterEnerStat,

chaired by the International Energy Agency (IEA), were the key content providers to IRES in

accordance with the mandates given to them by the Commission. The London Group and the

United Nations Expert Group on International Economic and Social Classifications were consulted

in the process as well.

1.33 UNSD coordinated and organized worldwide consultations, provided substantive inputs on

various topics and was responsible for consolidating and editing various successive versions of the

draft IRES.

1.34 Guiding principles for the development of IRES. The Oslo Group agreed on the following

principles to guide the preparation of IRES:

(a) The needs of major user groups should be considered as a starting point and be taken

into account, to the maximum extent possible, to ensure that the data compiled

according to the new recommendations are policy relevant, meet the needs of the

energy community (both producers and users) and provide a solid foundation for the

integration of energy statistics into a broader accounting framework;

(b) The development should be conducted in close consultation with both national

statistical offices and national energy agencies, as well as with the relevant international

and supranational organizations;

(c) While providing recommendations on data items and their definitions, care should be

taken so that: (i) necessary data sources are generally available in countries to compile

such data; (ii) the collection of such data items does not create a significant additional

reporting burden; and (iii) the collection procedures can be implemented by most

countries to ensure improved cross-country comparability;

(d) The development should be seen in the context of promoting an integrated approach in

the national statistical system which requires, to the extent possible, the use of

harmonized concepts and classifications and standardized data compilation methods in

order to achieve maximum efficiency and minimize the reporting burden;

(e) Additional guidance on more practical/technical matters to assist countries in the

implementation of IRES should be provided in the forthcoming Energy Statistics

Compilers Manual (ESCM). During the revision process, the Oslo Group will decide on

what will be covered in ESCM and to what extent.

E. Structure of IRES

1.35 The IRES is structured in accordance with its objectives and contains eleven chapters and

three annexes. The content of each chapter is briefly described below.

12

1.36 Chapter 1. Introduction. This chapter provides background information, formulates the

objectives of IRES, describes its target audience and outlines its content. It is emphasized that the

main objective of IRES is to provide a firm foundation for the long-term development of energy

statistics as part of official statistics based on the United Nations Fundamental Principles of

Official Statistics. The chapter stresses the importance of energy statistics for sound decision- and

policy-making and identifies major user groups and their needs.

1.37 Chapter 2. Scope of Energy Statistics. The purpose of this chapter is to define the scope and

coverage of energy statistics. The chapter recommends treating energy statistics as a complete

system to understand energy stocks and flows, energy infrastructure, performance of the energy

industries and the availability of energy resources. The scope of energy statistics is defined in

terms of energy products, energy flows, the reference territory, energy industries, energy

consumers, energy resources and reserves.

1.38 Chapter 3. Standard International Energy Product Classification. This chapter introduces

the Standard International Energy Product Classification (SIEC), which organizes the

internationally agreed definitions of energy products into a hierarchical classification system,

reflects the relationships between them and provides a coding system for use in data collection and

data processing. The chapter describes the SIEC classification scheme and its relationships with the

Harmonized Commodity Description and Coding System 2007 (HS 2007) and the Central Product

Classification, Version 2 (CPC Ver.2). A supplementary characterization of SIEC products as

primary and secondary products and renewable and non-renewable products is provided in Annex

A.

1.39 Chapter 4. Measurement Units and Conversion Factors. This chapter describes physical

units of measurement for the different products, recommends common units of measurement, and

provides recommendations on the calculation and reporting of calorific values. In the absence of

specific calorific values, default calorific values are presented.

1.40 Chapter 5. Energy flows. This chapter contains a general overview of the process through

which energy products appear on national territory, are traded and are consumed within a country.

It provides definitions of energy flows such as energy production, transformation, non-energy use,

final energy consumption, etc. The chapter describes the main groups of economic units relevant to

energy statistics (e.g., energy industries, other energy producers and energy consumers), and

provides necessary information to facilitate the understanding of the data items presented in

Chapter 6.

1.41 Chapter 6. Statistical Units and Data Items. This chapter contains recommendations on the

statistical units (and their characteristics) and the reference list of data items for collection. The list

covers: characteristics of statistical units; data items on energy stock and flows; data items on

production and storage capacity; data items for the assessment of economic performance; and data

items on reserves of mineral and energy resources. This chapter provides a basis for the subsequent

chapters on data collection and compilation (Chapter 7), as well as the construction of energy

balances (Chapter 8). While Chapter 5 provides general definitions of flows, Chapter 6 explains

13

possible exceptions and details to be taken into account for specific products in the definition of

particular data items.

1.42 Chapter 7. Data collection and compilation. This chapter reviews the different elements for

the production of high-quality energy statistics. The importance and principles of an effective

institutional and legal framework are emphasized and promoted. The chapter provides an overview

of the data collection strategies and focuses on the main types of data sources (e.g., surveys,

administrative data, etc.) and key elements of the data compilation methods. Details on more

practical aspect of data collection/compilation, such as the estimation methods and imputation, are

deferred to the ESCM.

1.43 Chapter 8. Energy Balances. This chapter describes the importance of energy balances for

making informed policy decisions and their role in organizing energy statistics in a coherent

system. It contains recommendations on the compilation of balances based on concepts,

definitions, classifications and data items described in the previous chapters. The chapter covers

the presentation of energy supply, transformation and consumption, as well as other flows in the

format of an energy balance.

1.44 Chapter 9. Data Quality Assurance and Metadata. This chapter describes the main

dimensions of energy data quality and provides recommendations on how to set up a national

energy data quality framework, including development and use of indicators of quality and data

quality reporting. The importance of metadata availability for ensuring a high quality of energy

statistics is stressed as well.

1.45 Chapter 10. Dissemination. This chapter formulates recommendations on energy statistics

dissemination mechanisms, addressing data confidentiality, data access, release schedules, data

revisions, dissemination formats and reporting to international/regional organizations.

1.46 Chapter 11. Uses of Basic Energy Statistics and Balances. This chapter provides some

examples of important uses of energy statistics and balances. The use of energy statistics and

energy balances for the compilation of energy accounts of the System of Environmental-Economic

Accounting for Energy (SEEA-Energy) is discussed, including a brief elaboration of conceptual

differences. This chapter also presents examples of energy indicators linked to the social, economic

and environmental dimensions and to the compilation of statistics on greenhouse gas (GHG)

emissions.

1.47 IRES contains three annexes that provide: (i) the characterization of SIEC products as

primary and secondary products, as well as renewable and non-renewable products; (ii) tables on

conversion factors, calorific values and measurement units; and (iii) a description of commodity

balances. A bibliography is also provided.

F. Summary of recommendations

1.48 IRES contains numerous recommendations and encouragements on various issues relevant

to the collection, compilation and dissemination of energy statistics. The table below is intended to

14

assist the reader by highlighting the main recommendations and encouragements. It should be

noted, however, that, in many cases, the correct interpretation of a particular recommendation or

encouragement requires familiarity with the full IRES text.

Table 1.1 Summary of the main recommendations and encouragements contained in IRES

Para.

Recommendations and encouragements

Chapter 1. Introduction

1.17 To ensure high quality in energy statistics, countries are encouraged to take steps to advance from the

collection of selected data items used primarily for internal purposes by various specialized energy

agencies to the establishment of an integrated system of multipurpose energy statistics as a part of

their official statistics in the context of the United Nations Fundamental Principles of Official

Statistics and on the basis of appropriate institutional arrangements.

1.20 It is recommended that international organizations play an active role in IRES implementation and

assist countries in developing energy statistics work programmes as part of their national official

statistics through, for example, the preparation of training materials and organizing regular training

programmes, including regional workshops, and assisting countries in the sharing of expertise gained

in this process.

1.22 It is recommended that official energy statistics be treated as a public good and the agencies

responsible for their dissemination ensure that the public has convenient access to those statistics.

1.49 The present recommendations should be implemented by countries in a way appropriate to their own

circumstances, including identified user needs, resources, priorities and respondent burden.

Chapter 2. Scope of energy statistics

2.6 Even though data on energy resources and reserves are generally collected by specialized

governmental agencies (e.g., geological institutes), which are assigned the responsibility of monitoring

the depletion of energy resources, such data should be obtained and included in the energy data

warehouse.

2.7 The energy data collection should be organized in close collaboration with other data collection

activities carried out in a given country (e.g., with programmes of enterprise or establishment censuses

and surveys based on the relevant recommendations adopted by the United Nations Statistical

Commission) to avoid duplication of efforts and ensure overall coherence of official statistics.

2.9 It is recommended that energy products refer to products exclusively or mainly used as a source of

energy. They include forms suitable for direct use (e.g., electricity and heat) and energy products that

release energy while undergoing some chemical or other process (including combustion). By

convention, energy products also include peat, biomass and waste when and only when they are used

for energy purposes.

Chapter 3. Standard International Energy Products Classification

3.1 Internationally agreed definitions of energy products and their classification should be promoted as a

basic tool for energy statistics compilation and dissemination both at national and international levels.

Chapter 4. Measurement units and conversion factors

4.27 The only energy unit in the International System of Units is the joule and it is usually used in energy

statistics as a common unit, although other energy units are sometimes also applied (e.g., toe, GWh,

Btu, calories, etc.). The use of the joule as a common unit is recommended.

4.28 It is recommended that national and international agencies in charge of energy statistics and any other

organizations that advise them or undertake work for them, always clearly define the measurement

units, as well as the common units used for presentational purposes in various publications and in

electronically disseminated data. The conversion factors and the methods used to convert original

physical units into the chosen common unit or units should be described in energy statistics metadata

and be readily accessible to users. In addition, it should be made clear whether energy units are

defined on a gross or net calorific basis.

15

4.34 It is recommended that, when expressing the energy content of energy products in terms of a common

energy unit, net calorific values (NCVs) be used in preference to gross calorific values (GCVs). Where

available, it is strongly encouraged to report both gross and net calorific values.

4.38 It is recommended that countries collect data in original units together with data on specific calorific

values. Default calorific values should only be used as a last resort in the absence of specific values,

acknowledging that this simplification will affect the precision of the published figures.

4.39 It is recommended that metadata be provided on the methods used in all calculations and conversions

undertaken to arrive at the disseminated data in order to ensure transparency and clarity and to enable

comparability. In particular, this would include the conversion factors between original and presented

units, whether they are on a gross or net calorific basis, and any use of default values.

4.44 Since calorific values may change according to the type of flow, countries are encouraged to collect

calorific values at least on production, imports and exports.

4.60 Due to the wide variability in composition in ash and moisture content of general animal and vegetal

wastes across countries, it is recommended that these products be reported to international

organizations in an energy unit (preferably TJ) rather than their natural units.

4.65 While no specific measurement unit is recommended for national data collection, certain units are

recommended for data dissemination. If necessary, countries may use other units, as long as

appropriate conversion factors are provided. For each main category of energy products, the

recommended unit for dissemination is provided in Table 4.4.

4.67 It is recommended that countries report to international organizations both physical quantities of fuels

and their country-specific (and where necessary flow-specific) calorific values.

Chapter 5. Energy Flows

5.9 It is recommended that countries follow the definitions of energy flows in their official energy

statistics as closely as possible. Any deviations should be reflected in countries’ energy metadata.

5.23 It is recommended that energy industries be defined as consisting of economic units whose principal

activity is primary energy production, transformation of energy, or distribution of energy, with the

additions described in para. 5.26.

5.24 It is recommended that the collection, compilation and dissemination of statistics describing the main

characteristics and activities of energy industries be considered as part of official energy statistics.

5.26 It is recommended that countries identify, as far as feasible and applicable, the energy industries

listed in the left column of Table 5.1.

5.77 It is recommended that countries, where “other energy producers” account for a significant part of

total energy production, make efforts to obtain from them the detailed data and incorporate them in

their official energy statistics, including in energy balances.

5.80 It is recommended that countries identify, as far as feasible and applicable, the groups of energy

consumers as listed in Table 5.3.

Chapter 6. Statistical Units and Data Items

6.3 It is recommended that countries use the reference list of data items for selecting data items for use in

their national energy statistics programmes, in accordance with their own circumstances, respondent

load and available resources. It is further recommended that the data items be selected in a way to

allow for an adequate assessment of the country’s energy situation, reflect main energy flows specific

to the country and enable, as a minimum, the compilation of energy balances in an aggregated format.

6.5 Countries are encouraged to use analytical units as statistical units, as necessary and feasible, in order

to improve the quality of their energy statistics.

6.9 In general, it is recommended that large enterprises engaged in many economic activities that belong

to different industries be broken up into one or more establishments, provided that smaller and more

homogeneous units can be identified for which data on energy production or other activities attributed

to energy industries may be meaningfully compiled.

6.21 The establishment is recommended as the statistical unit for energy statistics because it is the most

detailed unit for which the range of data required is normally available.

6.75 For analytical purposes, countries are encouraged to compile information on the components of the

different prices of energy products.

6.78 It is recommended that, in statistical questionnaires, countries refer to the specific names or

descriptions of taxes as they exist in their national fiscal systems.

16

6.84 In order to maintain consistency with the valuation principles for output (production) of other

international recommendations on business statistics and national accounts, it is recommended that

countries compile the output of establishments at basic prices. However, in circumstances where it is

not possible to segregate “taxes and subsidies on products” and “other taxes on production”, valuation

of output at factor cost can serve as a second best alternative.

Chapter 7. Data collection and compilation

7.5 It is recommended that national agencies responsible for the compilation and dissemination of energy

statistics should, whenever appropriate, actively participate in the discussions on national statistical

legislation or relevant administrative regulations in order to establish a solid foundation for high

quality and timely energy statistics, with a view to mandatory reporting, whenever appropriate, and

adequate protection of confidentiality.

7.10 It is recommended that countries develop an appropriate interagency coordination mechanism which,

while taking into account existing legal constraints, would systematically monitor performance of the

national system of energy statistics, motivate its members to actively participate in the system, develop

recommendations focused on improving the system’s functioning, and have the authority to implement

such recommendations.

7.13 It is recommended that countries consider the establishment of the institutional arrangements

necessary to ensure the collection and compilation of high quality energy statistics as a matter of high

priority and periodically review their effectiveness. The national agency that has the overall

responsibility for the compilation of energy statistics should periodically review the definitions,

methods and the statistics themselves to ensure that they comply with relevant international

recommendations and recognized best practices, are of high quality, and are available to users in a

timely fashion.

7.18 It is recommended, as applicable, that at least the following three reporter groups be distinguished:

energy industries, other energy producers and energy consumers.

7.29 Countries are encouraged to conduct higher frequency (infra-annual) collections on a regular basis

within the identified priority areas of energy statistics due to their critical importance for the timely

assessment of a fast changing energy situation.

7.33 Close collaboration between energy statisticians and compilers of industrial statistics, as well as

statisticians responsible for conducting household, labour force and financial surveys, is of paramount

importance and should be fully encouraged and systematically promoted.

7.39 It is recommended that countries make efforts to establish a programme of sample surveys that would

satisfy the needs of energy statistics in an integrated way (i.e., as part of an overall national sample

survey programme of enterprises and households) to avoid duplication of work and minimize the

response burden.

7.41 To ensure the regular conduct of energy surveys, it is recommended that the periodicity of such

surveys be established from the very beginning. Countries are encouraged to ensure that the survey

design is optimized, keeping in mind the desirable use and inferences from the expected results, while

information not essential for the survey purposes should be avoided as much as possible.

7.47 It is recommended, as the best option, that the frame for every list-based enterprise survey for energy

industries be derived from a single general-purpose statistical business register maintained by the

statistical office, rather than from stand-alone registers for each individual survey.

7.48 For countries not maintaining a current up-to-date business register, it is recommended that the list of

enterprises drawn from the latest economic census and amended as necessary, based on relevant

information from other sources, be used as a sampling frame.

7.67 It is recommended that compilers of energy statistics use imputation as necessary, with the

appropriate methods consistently applied. It is further recommended that these methods comply with

the general requirements as set out in international recommendations for other domains of economic

statistics, such as the International Recommendations for Industrial Statistics 2008.

7.68 As the application of estimation procedures is a complex undertaking, it is recommended that

specialist expertise always be sought for this task.

Chapter 8. Energy balances

17

8.1 The energy balance should be as complete as possible so that all energy flows are, in principle,

accounted for. It should be based firmly on the first law of thermodynamics, which states that the

amount of energy within any closed system is fixed and can neither be increased nor diminished unless

energy is brought into or sent out from that system.

8.5 It is recommended that countries collect data at the level of detail that allows for the compilation of a

detailed energy balance, as presented in Table 8.1. When such a level of detail is not available or

practical, it is recommended that countries, at a minimum, follow the template of the aggregated

energy balance presented in Table 8.2.

8.9 (a) The energy balance is compiled with respect to a clearly defined reference period. In this respect, it is

recommended that countries, as a minimum, compile and disseminate an energy balance on an annual

basis.

8.9(h) All entries in the energy balance should be expressed in one energy unit (it is recommended that the

Joule be used for this purpose, although countries could use other energy units, such as toe, tce, etc.).

The conversion between energy units should be through the application of appropriate conversion

factors (see Chapter 4) and the applied factors should be reported with the energy balance to make any

conversion from physical units to Joules or other units transparent and comparable.

8.9(j) In the case of electricity generation from primary heat (nuclear, geothermal and concentrating solar), it

is recommended that an estimate of the heat input be used based on an efficiency of 33 per cent for

nuclear and concentrating solar, and 10 per cent for geothermal as a default, unless country- or case-

specific information is available.

8.10 While the structuring of an energy balance depends on a country’s energy production and consumption

patterns and the level of detail that the country requires, it is recommended that common approaches

be followed to ensure international comparability and consistency (see Section 8.C).

8.12 While different columns (except “Total”) represent various energy products, they might be grouped

and sequenced in a way that adds to the analytical value of the balance. In this connection, it is

recommended that:

(a) Groups of energy products be mutually exclusive and based on SIEC;

(b) The column “Total” follow the columns for individual energy products (or groups of products);

(c) The column “Total” be followed by supplementary columns containing additional subtotals such

as “renewables”. The definition of such subtotals and any additional clarification on the column’s

coverage should be provided in appropriate explanatory notes.

8.14 It is recommended that an energy balance contain three main blocks of rows as follows:

(a) Top block – flows representing energy entering and leaving the national territory, as well as stock

changes to provide information on the supply of energy on the national territory during the reference

period;

(b) Middle block – flows showing how energy is transformed, transferred, used by energy industries

for own use and lost in distribution and transmission;

(c) Bottom block – flows reflecting final energy consumption and non-energy use of energy products.

8.22 As countries may adopt different conventions for the calculation of the change in energy stocks, it is

recommended that necessary clarification be provided in country metadata. Countries are

encouraged to collect comprehensive data on stock changes from large companies, private or public,

as a minimum.

8.29 It is recommended that countries show in their balances, to the extent possible and applicable, energy

transformation by the categories of plants, as presented in para. 5.70.

8.30 It is recommended that: (a) energy entering transformation processes (e.g., fuels into electricity

generation and heat generation, crude oil into oil refineries for the production of oil products, or coal

into coke ovens for the production of coke and coke oven gas) be shown with a negative sign to

represent the input and (b) energy that is an output of transformation activities be shown as a positive

number.

8.35 It is recommended that final energy consumption be grouped into three main categories: (i)

manufacturing, construction and non-fuel mining industries, (ii) transport and (iii) other, and further

disaggregated according to countries’ needs (see Chapter 5 for more detail).

8.36, 8.40,

8.42

Taking into account the needs of energy policy makers and to ensure cross country comparability of

energy balances, it is recommended that, in their energy balance, countries show final energy

consumption disaggregated according to the groups shown in Table 5.3.

18

8.37 In the energy balances, data for energy use for transport should be disaggregated by mode of transport

as shown in Table 5.4.

8.45 The reasons for a large statistical difference should be examined because this indicates that the input

data are inaccurate and/or incomplete.

8.48 When only main aggregates have to be shown, it is recommended that the template presented in

Table 8.2 be used, as applicable, to ensure international comparability and assist in monitoring

implementation of various international agreements and conventions.

8.51 It is recommended that accuracy requirements applicable to basic energy data used in the balance be

clearly described in the energy statistics metadata of the country.

8.52 It is recommended that countries estimate missing data in order to maintain the integrity of the

balance and follow the imputation methods and general principles established in other areas of

statistics, as well as good practices applicable to energy statistics.

8.53 It is recommended that countries provide a summary of the performed reconciliation in the energy

balance metadata to ensure the transparency of the energy balance preparation and to assist users in

proper interpretation of the information contained therein and its relationship with other disseminated

statistics.

8.54 It is recommended that the suitability of foreign merchandise trade statistics always be reviewed and

available data used to the maximum extent possible to avoid duplication of efforts and publication of

contradictory figures. It is further recommended that energy and trade statisticians regularly review

data collection procedures to ensure that the needs of energy statistics are met to the extent possible.

8.55 While countries may use various formats of commodity balances depending on their needs and

circumstances, it is recommended that the format of the energy balance and all applicable concepts

defined in IRES be consistently used in the compilation of a commodity balance to ensure data

consistency.

8.59 It is recommended that commodity balances be constructed at the national level for every energy

commodity in use, however minor, with certain commodities aggregated for working purposes.

Chapter 9. Data quality assurance and metadata

9.13 Countries are encouraged to develop their own national quality assurance frameworks based on the

approaches described in Chapter 9 or other internationally recognized approaches, taking into

consideration their specific national circumstances.

9.15 It is recommended that if, while compiling a particular energy statistics dataset, countries are not in a

position to meet the accuracy and timeliness requirements simultaneously, they produce provisional

estimates, which would be available soon after the end of the reference period but would be based on

less comprehensive data content.

9.20 Countries are encouraged to develop or identify a set of quality measures and indicators that can be

used to describe, measure, assess, document and monitor over time the quality of their energy statistics

outputs and make them available to users.

9.21 Countries are encouraged to select practical sets of quality measures and indicators that are most

relevant to their specific outputs and can be used to describe and monitor the quality of the data over

time.

9.27 Countries are encouraged to regularly issue quality reports as part of their metadata.

9.28 It is recommended that some form of quality review of energy statistics programmes be undertaken

periodically, for example every four to five years or more frequently, if significant methodological or

other changes in the data sources occur.

9.38 It is recommended that different levels of metadata detail be made available to users to meet the

requirements of the various user groups.

9.41 The development of capacity in countries to disseminate national data and metadata using web

technology and Statistical Data and Metadata Exchange (SDMX) standards such as cross domain

concepts is recommended as a means to standardize and reduce the international reporting burden.

9.42 It is recommended that countries accord high priority to the development of metadata, to keeping

them up-to-date, and to consider the dissemination of metadata to be an integral part of the

dissemination of energy statistics. In consideration of the integrated approach to the compilation of

economic statistics, it is also recommended that a coherent system and a structured approach to

metadata across all areas of statistics be developed and adopted, focusing on improving their quantity

and coverage.

19

Chapter 10. Dissemination

10.2 The dissemination policy should be user oriented, reaching and serving all user groups, and provide

quality information. While each user group has different needs and preferred data formats, the goal

should be to reach all kinds of users rather than targeting specific audiences. Therefore, both

publications and web sites should be designed as clearly as possible for the general public, as well as

for researchers and the media.

10.3 Countries are encouraged to work closely with the user community by conducting vigorous outreach

campaigns, including building stable and productive relationships with users and key stakeholders.

10.4 It is recommended that countries conduct user satisfaction surveys with the periodicity established by

the responsible national agency.

10.12 Countries are encouraged to develop their own statistical disclosure methods that best suit their

specific circumstances.

10.15 It is recommended that countries implement the general rules on statistical confidentiality in such a

way as to promote access to data while ensuring confidentiality, in accordance with the recommended

criteria in paragraph 10.15.

10.16 It is recommended that countries make their energy data available on a calendar basis compatible

with the practice adopted by the statistical authority of the compiling country in other areas of

statistics, preferably according to the Gregorian calendar and consistent with the recommendations set

out in this publication. For international comparability, countries that use the fiscal year should

undertake efforts to report annual data according to the Gregorian calendar.

10.17 It is recommended that countries announce in advance the precise dates on which various series of

energy statistics will be released. This advance release schedule should be posted at the beginning of

each year on the website of the national agency responsible for the dissemination of the official energy

statistics.

10.19 Taking into account both policy needs and prevailing data compilation practices, countries are

encouraged to:

(a) Release their monthly data within two calendar months after the end of the reference month, at

least at the most aggregated level;

(b) Release their quarterly data within three calendar months after the end of the reference quarter;

and

(c) Release their annual data within fifteen calendar months after the end of the reference year.

10.20 The early release of provisional estimates within one calendar month for monthly data on specific

flows and products and within nine to twelve calendar months for annual data is encouraged.

10.22 Provisional data should be revised when new and more accurate information becomes available. Such

practice is recommended if countries can ensure consistency between provisional and final data.

10.24 With respect to routine revisions, it is recommended that countries develop a revision policy that is

synchronized with the release calendar. It is recommended that these revisions should be subject to

prior notification to users to explain why revisions are necessary and to provide information on their

possible impact on the released outputs.

10.25 Countries are encouraged to develop a revision policy for energy statistics that is carefully managed

and well coordinated with other areas of statistics.

10.26 It is recommended that energy statistics be made available electronically, but countries are

encouraged to choose the dissemination format that best suits their users’ needs.

10.27 Countries are encouraged to harmonize their data with international standards, follow the

recommendations provided in Chapter 9 on data quality assurance and metadata for energy statistics

and develop and disseminate metadata in accordance with the recommendations provided.

10.28 It is recommended that countries disseminate their energy statistics internationally as soon as they

become available to national users and without any additional restrictions. To ensure a speedy and

accurate data transfer to international and regional organizations, it is recommended that countries

use the Statistical Data and Metadata Exchange (SDMX) format in the exchange and sharing of their

data.

Chapter 11 Uses of basic energy statistics and balances

11.28 Due to differences between basic energy statistics/energy balances and energy accounts, countries are

encouraged to clearly document and make available the methods used for the reallocation and

adjustment of data provided by basic energy statistics and balances to energy accounts.

20

11.33 The list of indicators presented in chapter 11 is not exhaustive. Countries are encouraged to develop

the list of relevant indicators according to their policy concerns and data availability.

11.34 For Greenhouse gas emissions, countries are encouraged to make additional efforts to verify the

compiled data and make any necessary adjustments in order to ensure that the calculated emissions are

internationally comparable.

G. Implementation and revision policy

1.49 The present recommendations should be implemented by countries in a way appropriate to

their own circumstances, including identified user needs, resources, priorities and respondent

burden. Additional guidance on more practical/technical matters (e.g., good practices, country case

studies, etc.) relevant to the implementation of IRES will be provided in the ESCM, which is

envisaged to be updated more frequently than IRES.

1.50 Recommendations and encouragements. For the purposes of IRES, the term

“recommended” refers to a standard with which countries should comply, while the term

“encouraged” indicates a desirable practice which is not part of the standard as such. With respect

to issues that might be relevant to compilers and users of energy statistics but that are not explicitly

covered in IRES, countries are encouraged to develop their own treatments and clearly document

them in their metadata.

1.51 The IRES updating process is foreseen as a recurrent and well-organized procedure. While

preparation of editorial amendments and clarifications beyond dispute is the responsibility of

UNSD, any substantive changes in IRES will be discussed with countries and relevant working

groups before being endorsed by the United Nations Expert Group on Energy Statistics and

submitted to the United Nations Statistical Commission for adoption.

21

Chapter 2. Scope of energy statistics

A. Energy and energy statistics

2.1 Energy and its forms. Energy, as generally understood in physics, is the capacity of a

physical system to do work. Energy exists in different forms, such as light, heat and motion, but

they can all be put into two categories: potential energy (e.g., the energy “stored” in matter) and

kinetic energy (the energy of motion). Examples of potential energy are chemical energy (energy

stored in the bonds of atoms and molecules), water stored in a reservoir at a height (the potential

energy stored is released when the water is allowed to fall/flow through a turbine) and nuclear

energy (energy stored in the nucleus of an atom). Examples of kinetic energy are wind and falling

water. When wind is blowing, it contains kinetic energy. Similarly, when the potential energy of a

reservoir of water is released it becomes kinetic energy which is then captured in a turbine.

2.2 Energy in the statistical context. Not all energy is an object of statistical observation.

Energy existing in nature and not having a direct impact on society is not measured and monitored

as part of energy statistics; however, national practices in this respect might differ. In order to assist

countries in making their energy statistics more policy relevant and internationally comparable, this

chapter provides recommendations on the scope of energy statistics by describing which kinds of

energy are to be statistically observed and discusses related concepts and boundary issues. In this

connection, it should be noted that the term “energy statistics” is widely used, not only by energy

statisticians, but also by compilers of other statistics, policy makers and research institutions. Its

meaning, as understood by different groups, varies from a rather narrow interpretation focusing on

production and consumption of a few main energy products to broader versions covering basic

energy statistics, energy balances and energy accounts.

2.3 Scope of energy statistics in IRES. The recommendations contained in this publication are

focused on basic energy statistics and energy balances. The basic energy statistics refer to statistics

on energy stocks and flows, energy infrastructure, performance of the energy industries, and the

availability of energy resources within the national territory of a given country during a reference

period. Energy balances are an accounting framework for the compilation and reconciliation of

data on all energy products entering, exiting and used within that territory. IRES provides a brief

description of some of the uses of the basic energy statistics and energy balances, such as the

compilation of environmental-economic accounts, energy indicators and greenhouse gas emissions,

and identifies, wherever necessary, the main conceptual differences.

2.4 IRES promotes a multipurpose approach to energy statistics, in particular by emphasizing

the idea of an energy data warehouse as an efficient way of meeting the data needs of energy policy

makers and energy analysts, as well as of compilers of energy accounts and national accounts.

22

Such an energy data warehouse may provide convenient access to data on energy stocks and flows,

as well as to selected statistics on energy producers and users (e.g., on energy infrastructure,

employment and capital formation), selected data about the energy market (e.g., energy prices),

statistics on reserves of mineral and energy resources, etc. It is recognized that additional data

might be needed to respond to specific policy concerns and/or analytical questions. Countries may

wish to identify such items and collect them according to their priorities and available resources.

2.5 Energy prices. IRES acknowledges the importance of the availability of reliable data on

energy prices and their movements (e.g., import and export prices of energy products, consumer

prices and their respective indices, etc.), as they are vital for monitoring energy markets and

developing effective energy policies.

2.6 Mineral and energy resources. Energy resources refer to “all non-renewable energy

resources of both inorganic and organic origins discovered in the earth’s crust in solid, liquid and

gaseous form.”14

Energy reserves are part of the resources which, based on technical, economic

and other relevant (e.g., environmental) considerations, could be recovered and for which

extraction is justified to some extent. The exact definition of reserves depends on the kind of

resources in focus. Even though data on energy resources and reserves are generally collected by

specialized governmental agencies (e.g., geological institutes), which are assigned the

responsibility of monitoring the depletion of energy resources, such data should be obtained and

included in the energy data warehouse.

2.7 Further elaboration of the scope of basic energy statistics is provided in the reference list of

data items presented in Chapter 6. It contains all items desirable for the compilation and

dissemination of such statistics and serves as a reference list for countries to select the relevant data

items for national compilation, taking into account their needs, priorities and resources. Given the

inter-linkages with other statistical domains (such as industrial and trade statistics), the concepts

presented in IRES are, to the extent possible, harmonized with those of other statistical domains. It

should be emphasized that the actual energy data collection should be organized in close

collaboration with other data collection activities carried out in a given country (e.g., with

programmes of enterprise or establishment censuses and surveys based on the relevant

recommendations adopted by the United Nations Statistical Commission, such as the International

Recommendations for Industrial Statistics 2008 (UN 2009b), the International Recommendations

for Distributive Trade Statistics 2008 (UN 2009a), or the International Merchandise Trade

Statistics, Rev.2 (UN 1998)), to avoid duplication of efforts and ensure overall coherence of official

statistics.

14 ECE (2004) United Nations Framework Classification for Fossil Energy and Mineral Resources, page 1, available

at: http://www.unece.org/fileadmin/DAM/energy/se/pdfs/UNFC/UNFCemr.pdf.

23

B. Basic concepts and boundary issues: an overview

2.8 Energy statistics is a specialized statistical domain with a long history of usage of specific

concepts and related terminology firmly incorporated in data compilation and dissemination and

widely accepted by the main users of energy statistics. In some cases, the terms used in energy

statistics have different meaning in other statistical areas, such as in national accounts (See

paragraph 5.16 for the example of “stocks”.). In all cases in which such a situation exists, the

differences in the term’s meaning will be acknowledged and explained.

2.9 Energy products. The term “products” is understood in the same way as in economic

statistics where it refers to all goods and services which are the result of production.15

Energy

products are a subset of products. As a general guideline, it is recommended that energy products

refer to products exclusively or mainly used as a source of energy. They include forms suitable for

direct use (e.g., electricity and heat) and energy products that release energy while undergoing

some chemical or other process (including combustion). By convention, energy products also

include peat, biomass and waste when and only when they are used for energy purposes (See

Chapter 3 for details and classification of energy products.).

2.10 Since a number of energy products are transformed into other kinds of energy products

prior to their consumption, a distinction is made between primary and secondary energy products.

This distinction is necessary for various analytical purposes, including for avoiding the double

counting of energy production in cross-fuel tabulations, such as energy balances. Energy products

can be obtained from both renewable (e.g., solar, biomass, etc.) and non-renewable sources (e.g.,

coal, crude oil, etc.). It is important for both energy planning and environmental concerns to

distinguish between renewable and non-renewable energy products, as well as to distinguish

“infinite” renewable sources such as solar from cyclical renewable sources such as biomass. For

definitions and additional information on primary, secondary, renewable and non-renewable energy

products, see Chapter 5 and Annex A.

2.11 Boundary of energy products. The description of the boundary of the universe of energy

products is not always straightforward. For example, corncobs can be: (1) combusted directly to

produce heat; (2) used in the production of ethanol as a biofuel, (3) consumed as food, or (4)

thrown away as waste. To assist countries in the delineation of energy products, IRES presents the

Standard International Energy Product Classification (SIEC), as well as the definitions of such

products (see Chapter 3). According to the scope of SIEC, corncobs, as such, are considered energy

products for the purpose of energy statistics only in case (1) above, that is when they are

combusted directly to produce heat (c.f. paragraph 3.10). In all other cases, they either do not fall

within the boundary of energy statistics (when used as a source of food), or they enter the boundary

of energy statistics as a different product (e.g. ethanol).

15 See SNA 2008, para. 6.24, for a general definition of production and para. 5.10 of this publication for a definition of

energy production.

24

2.12 Energy flows. In general, energy flows describe the various activities of economic actors

undertaken on the national territory of a compiling country, such as production of energy products,

their import, export and use. It is crucial that official energy statistics establish a broad

understanding of the totality of energy flows and their impact on society and the environment.

Chapter 5 of IRES presents energy flows in more detail.

2.13 Production boundary. As a general guideline, the energy production boundary includes the

production of energy products by any economic unit, including households, whether or not the

production is: (i) their principal, secondary or ancillary activity; and/or (ii) carried out for sale or

delivery to other economic units or for own use. The definition of energy production and related

concepts is provided in Chapter 5.

2.14 Reference territory. In general, the term “reference territory” defines the geographical scope

of the statistics compiled and the criteria for allocating selected statistics to a particular territory.

Energy statistics have historically responded, among others, to the policy concerns of the physical

availability of energy and its uses within the territory of a country. Thus, the criteria for allocating

certain statistics to the country follow the physical location of the units involved. The reference

territory used in energy statistics and energy balances is the national territory and is defined as the

geographic territory under the effective economic control of the national government. It comprises:

(a) The land area;

(b) Airspace;

(c) Territorial waters, including areas over which jurisdiction is exercised through fishing

rights and rights to fuels or minerals.

2.15 In a maritime territory, the economic territory includes islands that belong to the territory.

The national territory also includes any free trade zones, bonded warehouses or factories operated

by enterprises under customs control within the areas described above. By convention, the

territorial enclaves of other countries (e.g., embassies, consulates, military bases, scientific stations,

etc.) are treated as part of the national territory where they are physically located.16

2.16 The definition of reference territory recommended for energy statistics largely

approximates the economic territory of a country as used in economic statistics (see BPM6, para.

4.5 and SNA2008, para. 4.11). However, it should be noted that the concept of economic territory

in economic statistics (including in energy accounts) is used in conjunction with the concept of the

residence of the economic unit, which is the determining factor in the allocation of the statistics to

the economic territory.

2.17 Energy industries. Many countries publish indicators describing the activity of their energy

industries. However, individual country practices in defining the boundary of the energy industries

and the set of main indicators used to describe their activities may differ significantly. For example,

16 The latter differs from the treatment in national accounts (see SNA 2008, para. 4.11).

25

units considered to be part of energy industries may engage in activities that are not related to

energy. Even though these activities are not the main focus of energy statistics, they are addressed

by some of the data items described in Chapter 6. To improve international comparability of energy

statistics, specific recommendations on the definition of energy industries are provided in Chapter

5.

2.18 Energy production outside the energy industries. It should be stressed that energy can be

produced not only by energy industries but also by enterprises or establishments engaged in energy

production as a secondary or ancillary activity. For example, aluminium producers may have their

own power plant producing electricity primarily for internal consumption. A sugar cane processing

plant may use the remains after juice extraction from the sugar cane (bagasse) as a fuel for heating.

Similarly, waste materials (e.g., tires) can be incinerated with heat recovery at installations

designed for the disposal of mixed wastes or co-fired with other fuels. In order to have a complete

picture of the supply and demand of energy in a country, it is important that data on the production

of energy outside the energy industries are also collected and included in total energy production.

2.19 Energy uses and energy consumers. Energy products can be used for various purposes (e.g.,

as an input in the production of secondary energy products or for final consumption) and by

different user groups (e.g., various industries and households). The statistics on energy

consumption are of great importance for setting energy policy and for assessing the efficiency of

energy use, its environmental impact and others. The different types of energy consumers may be

grouped into various categories as necessary for analytical purposes. Uses of energy products and

user groups are further described in Chapter 5.

26

Chapter 3. Standard International Energy Product

Classification

A. Introduction

3.1 In order to ensure cross-country and temporal comparability of energy statistics, as well as

their comparability with other statistics, it is of paramount importance to have internationally

agreed definitions of energy products and their classification. Such definitions and classification

should be promoted as a basic tool for energy statistics compilation and dissemination both at

national and international levels.

3.2 This chapter presents the list of internationally agreed definitions of energy products and

the Standard International Energy Product Classification (SIEC), which arranges them in the

structure of a statistical classification. The chapter contains a description of the purpose and scope

of SIEC, and presents the classification criteria and the classification itself. In addition,

correspondences between SIEC and other international product classifications, such as the

Harmonized Commodity Description and Coding System (HS) and the Central Product

Classification (CPC) are provided. These correspondences facilitate the integration of energy

statistics with other economic statistics, thereby increasing their analytical value.

3.3 The correspondence with the HS is particularly useful as all international transactions in

energy products are defined in terms of HS. Many energy products are widely traded

internationally and energy companies are familiar with HS or its national equivalents. The

correspondence with HS is expected to facilitate data collection as the documentation that energy

importing/exporting companies provide for customs purposes includes the relevant HS codes. The

CPC aggregates the HS headings into product groupings which are of particular interest for

economic statistics and for various users.

3.4 The correspondence with HS and CPC presented in the chapter is indicative in the sense

that the HS and CPC categories are often broader in scope and may contain more elements than the

corresponding SIEC category.17

However, in the case of national or regional adaptations of the HS

(such as the European Combined Nomenclature), the correspondences may be more precise. This

applies in particular to the categories for refined petroleum products.

17 In Table 3.1, this is indicated with an asterisk next to the relevant link.

27

B. Purpose and scope of SIEC

3.5 The main purpose of SIEC is to serve as a basis for developing or revising national

classification schemes for energy products so as to make them compatible with international

standards and, consequently, to ensure significantly improved cross-country comparability of

energy data. SIEC is intended to be a multipurpose classification, meaning that individual SIEC

products and aggregates are defined to be suitable for the production of energy statistics under

different country circumstances and are relevant for the presentation and analysis of energy data in

various policy and analytical contexts. In this connection, it is recognized that SIEC should be

periodically reviewed and revised as necessary to reflect changes in the patterns of energy

production and consumption.

3.6 SIEC is designed to support the collection of data from data reporters and will: (i) facilitate

and standardize the compilation and processing of energy data by providing a uniform and

hierarchical coding system; (ii) ensure international comparability of disseminated national data;

and (iii) facilitate the linking of data on stocks and flows of energy products with data on

international trade in energy products and other economic statistics.

3.7 SIEC aims to cover all products necessary to provide a comprehensive picture of the

production, transformation and consumption of energy throughout an economy. Thus the scope of

SIEC consists of the following:18

(a) Fuels19

that are produced/generated by an economic unit (including households), and

are used or might be used as sources of energy; and

(b) Electricity that is generated by an economic unit (including households) and heat that is

generated and sold to third parties by an economic unit.

3.8 In order to define the scope of SIEC more precisely, the fuel coverage is further explained

below.

(i) All fossil fuels20

are within the scope of SIEC whether or not they are used for energy

purposes, but an exception is made for peat used for non-energy purposes, which should

be excluded.

18 SIEC does not cover underground deposits of energy resources, i.e. “non-renewable energy resources of both

inorganic and organic origin discovered in the earth’s crust in solid, liquid and gaseous form”. A classification of

underground mineral and energy resources is expected to be provided in the forthcoming SEEA-Energy (as part of the

general SEEA classification of “Natural Resources”), based on the definitions and classification of the United Nations

Framework Classification for Fossil Energy and Mineral Reserves and Resources (UNFC).

19 The term “fuel” refers to energy sources, whether primary or secondary, that must be subjected to combustion or

fission in order to release for use the energy stored up in them.

20 For the purposes of the discussion on the scope of SIEC, fossil fuels refer to coal, peat, oil and natural gas, even

though the inclusion of peat in fossil fuels is not universally accepted.

28

(ii) Products derived from fossil fuels are always within the scope of SIEC when used (or

intended to be used) for energy purposes, i.e. as fuels.

(iii) Products derived from fossil fuels used (or intended to be used) for non-energy

purposes are within the scope only if they are the output of energy industries (e.g.

refineries, gas plants or coal mining, coal manufacturing industries). They are included

because they explain how much an apparent supply of energy is used for other purposes

and allow for a complete assessment of the industries involved.

3.9 One example of products in category (iii) mentioned above are lubricants produced during

the refining of crude oil. Even though they are ordinarily used for non-energy purposes, their

production and consumption are recorded in energy statistics as this allows for the monitoring of

the different products obtained from the refinery intake of crude oil and the assessment of the part

of crude oil used for non-energy purposes. This is of relevance to energy planners, provided that

the consumption of these products is explicitly identified as non-energy use. On the other hand,

plastics, even if derived from a fossil fuel such as crude oil, are not considered within the scope of

SIEC as they are not an output of the refinery but are obtained by further processing of refinery

products by other industries.

3.10 Some fuels such as peat, waste,21

agricultural crops or other biomass are not of fossil origin.

Such products are within the scope of SIEC only when used for energy purposes. Thus, the

inclusion of these products in total energy production depends on their use, i.e. it is derived from

demand-side information.

3.11 In IRES, the term “energy product” is defined as any product covered by the scope of

SIEC, as formulated above.

3.12 It should be noted that, while SIEC provides definitions for all energy products, the scope

of individual applications of energy statistics may cover just a subset of SIEC. For example, while

SIEC includes nuclear fuels in the scope of energy products, they are not used in energy balances.

C. Classification criteria and coding system

3.13 The SIEC categories are designed to be exhaustive and mutually exclusive, so that any

product within the general scope would belong to one and only one SIEC category for any given

application.22

At the highest level, SIEC provides ten sections for different fuels, electricity and

21 Although, strictly speaking, part of waste can have a fossil origin, this part has already been accounted for as used

(often for non-energy purposes), thus it is treated together with other fuels of non-fossil origin to avoid imbalances in

the energy flows.

22 In some cases, demands for energy statistics require a different treatment for energy products. One such example

would be the classification of certain chemical compounds as individual oil products in terms of production, but as

refinery feedstocks in terms of inputs used. However, in both applications the treatment is unambiguous and the energy

balances include a mechanism to match these different flows. See also para. 3.14.

29

heat. The eight fuel categories represent broad fuel types distinguished by their origin and

characteristics, covering coal, peat and peat products, oil shale/oil sands, natural gas, oil, biofuels,

waste, nuclear fuels and other fuels. Where applicable, these fuel categories are further

disaggregated by physical characteristics (e.g. brown coal vs. hard coal) and stage of processing. In

the latter case, in each section the unprocessed products appear first (in order of the coding

system), followed by processed products. For some of the fuel categories, reference to the use is

made since the specifications of the product make it fit for certain types of use (e.g., kerosene and

its disaggregation into kerosene-type jet fuel and other kerosene).

3.14 Some products in SIEC, although physically similar, may be considered as different

products due to different origin or intended use. For instance, several of the included gases may

contain similar chemical components, but originate from different processes. This is the case for

the categories “natural gas” and “landfill gas”, both of which consist mainly of methane, but differ

in their source and method of production. Likewise, “natural gas liquids” and “liquefied petroleum

gas” both contain propane, but the latter category refers to a mix of gases that only contains

propane and butane, whereas the former category represents a less refined mix of gases. Another

example is the category “feedstocks” which may consist of energy products that can be found in

other categories (e.g., naphtha) but are characterized by the fact of being destined for a particular

use.

3.15 The top-level categories representing electricity and heat are not further disaggregated in

the classification. Unlike fuels, these products are not physical substances that can easily be

distinguished by origin, composition or intended purpose. Electricity and heat can be produced

through different processes, such as direct conversion of the energy in solar radiation, falling water

or release through combustion of fuels. The distinction between different production processes is

important for energy statistics and may be obtained by disaggregating information on the

production side (see Chapter 5 for more details).

3.16 The distinctions between primary and secondary energy products, as well as between

renewable and non-renewable energy products, are not explicit classification criteria in SIEC,

although in many cases a complete detailed SIEC category can clearly be assigned to one set. The

list of products considered primary or secondary and renewable or non-renewable is given in

Annex A.

Coding system

3.17 The SIEC hierarchy consists of four levels referred to as sections (the first level), divisions

(the second level), groups (the third level), and classes (the fourth level). The coding system

consists of a four-digit numerical code, with the first digit referring to the section, the first two

digits to the division, and so on. Thus, all four digits, taken together, designate a particular class of

the classification.

30

3.18 The hierarchy groups basic categories into higher-level aggregations according to the

criteria described above. The purpose is to provide a set of levels, with each level being used to

provide statistical information that is analytically useful.

31

Table 3.1: Standard International Energy Product Classification (SIEC)

SIEC Headings Correspondences

Section /

Division /

Group Class CPC Ver.2 HS 2007

0 Coal

01 Hard coal

011 0110 Anthracite 11010* 2701.11

012 Bituminous coal

0121 Coking coal 11010* 2701.19

0129 Other bituminous coal 11010* 2701.12

02 Brown coal

021 0210 Sub-bituminous coal 11030* 2702.10*

022 0220 Lignite 11030* 2702.10*

03 Coal products

031 Coal coke

0311 Coke oven coke 33100* 2704*

0312 Gas coke 33100* 2704*

0313 Coke breeze 33100* 2704*

0314 Semi cokes 33100* 2704*

032 0320 Patent fuel 11020 2701.20

033 0330 Brown coal briquettes (BKB) 11040 2702.20

034 0340 Coal tar 33200* 2706

035 0350 Coke oven gas 17200* 2705*

036 0360 Gas works gas (and other manufactured gases for

distribution)

17200* 2705*

037 Recovered gases

0371 Blast furnace gas 17200* 2705*

0372 Basic oxygen steel furnace gas 17200* 2705*

0379 Other recovered gases 17200* 2705*

039 0390 Other coal products 33500*,

34540*

2707,

2708.10*, .20*,

2712.90*

1 Peat and peat products

11 Peat

111 1110 Sod peat 11050* 2703*

112 1120 Milled peat 11050* 2703*

12 Peat products

121 1210 Peat briquettes 11050* 2703*

129 1290 Other peat products 11050*,

33100*,

33200*,

33500*

2703*, 2704*,

2706*,

2712.90*

2 Oil shale / oil sands


200 2000 Oil shale / oil sands 12030 2714.10

3 Natural gas

30 Natural gas

300 3000 Natural gas 12020 2711.11, .21

4 Oil

41 Conventional crude oil

410 4100 Conventional crude oil 12010* 2709*

42 Natural gas liquids (NGL)

420 4200 Natural gas liquids (NGL) 33420* 2711.14, .19*,

.29*

32

43 Refinery feedstocks

430 4300 Refinery feedstocks a a

44 Additives and oxygenates

440 4400 Additives and oxygenates 34131*,

34139*,

34170*, others

2207.20*,

2905.11,

2909.19*,

others

45 Other hydrocarbons

450 4500 Other hydrocarbons 12010*,

34210*

2709*, 2804.10

46 Oil products

461 4610 Refinery gas 33420* 2711.29*

462 4620 Ethane 33420* 2711.19*, .29*

463 4630 Liquefied petroleum gases (LPG) 33410 2711.12, .13

464 4640 Naphtha 33330* 2710.11*

465 Gasolines

4651 Aviation gasoline 33310* 2710.11*

4652 Motor gasoline 33310* 2710.11*

4653 Gasoline-type jet fuel 33320 2710.11*

466 Kerosenes

4661 Kerosene-type jet fuel 33342 2710.19*

4669 Other kerosene 33341 2710.19*

467 Gas oil / diesel oil and Heavy gas oil

4671 Gas oil / Diesel oil 33360* 2710.19*

4672 Heavy gas oil 33360* 2710.19*

468 4680 Fuel oil 33370 2710.19*

469 Other oil products

4691 White spirit and special boiling point industrial spirits 33330* 2710.11*

4692 Lubricants 33380* 2710.19*

4693 Paraffin waxes 33500* 2712.20*

4694 Petroleum coke 33500*,

34540*

2708.20*,

2713.11, .12

4695 Bitumen 33500* 2713.20

4699 Other oil products n.e.c. 33330*,

33350*,

33380*,

33420*,

33500*,

34540*

2707*,

2708.10*,

2710.11*,

2710.19*,

2711.14*,

2712.10*,

.20*,.90*,

2713.90

5 Biofuels

51 Solid biofuels

511 Fuelwood, wood residues and by-products

5111 Wood pellets 39280* 4401.30*

5119 Other Fuelwood, wood residues and by-products 03130, 31230,

39280*

4401.10,

4401.21, .22,

4401.30*

512 5120 Bagasse 39140* 2303.20*

513 5130 Animal waste 34654* 3101*

514 5140 Black liquor 39230* 3804.00*

33

515 5150 Other vegetal material and residues 01913, 21710,

34654*,

39120*,

39150*

0901.90*,

1213, 1802*,

2302*, 2304,

2305, 2306,

3101

516 5160 Charcoal 34510 4402

52 Liquid biofuels

521 5210 Biogasoline 34131*,

34139*,

34170*

2207.20*,

2905.11*, .13*,

.14*, 2909.19*

522 5220 Biodiesels 35490* 3824.90*

523 5230 Bio jet kerosene

529 5290 Other liquid biofuels

53 Biogases

531 Biogases from anaerobic fermentation

5311 Landfill gas 33420* 2711.29*

5312 Sewage sludge gas 33420* 2711.29*

5319 Other biogases from anaerobic fermentation 33420* 2711.29*

532 5320 Biogases from thermal processes

6 Waste

61 Industrial waste

610 6100 Industrial waste 3921,

39220,

39240,

39250,

39260,

39270,

39290

2525.30, 2601,

3915, 4004,

4012.20,

4115.20, 4707,

5003, 5103.20,

.30, 5104,

5202, 5505,

6309, 6310

62 Municipal waste

620 6200 Municipal waste 39910 3825.10

7 Electricity

70 Electricity

700 7000 Electricity 17100 2716

8 Heat

80 Heat

800 8000 Heat 17300 2201.90*

9 Nuclear fuels and other fuels n.e.c.

91 Uranium and plutonium


9101 Uranium ores 13000* 2612.10

9109 Other uranium and plutonium 33610,

33620,

33630*,

33710,

33720

2844.10,

2844.20,

2844.30*,

2844.50,

8401.30

92 Other nuclear fuels

920 9200 Other nuclear fuels 33630*,

33690*

2844.30*,

2844.40*

99 Other fuels n.e.c.

990 9900 Other fuels n.e.c.

Note: “Coal Products” refer to the products derived from hard coal and brown coal. “Peat products” refer to products

derived from peat. “Oil products” refer to products derived from the processing of conventional crude oil, NGLs, other

Hydrocarbons, refinery feedstock, etc.

34

Descriptions and definitions of the CPC and HS codes can be accessed on the websites of their custodians, the United

Nations Statistics Division (UNSD) and the World Customs Organization (WCO), respectively.

An asterisk (*) next to a CPC or HS code indicates that this link is a partial link only.

Revised correspondence tables between SIEC and updated versions of the CPC or HS are available on the UNSD

Classifications website at http://unstats.un.org/unsd/class.

a Since the definition of feedstocks is primarily based on intended use, giving an explicit CPC/HS link could be

misleading. Feedstocks may cover a wider range of products, including naphthas (HS 2710.11) and pyrolysis gasoline

(HS 2707.50) among others.

D. Definitions of energy products

3.19 The list of internationally agreed definitions of the products in SIEC is provided below. The

definitions are the result of the work of the Intersecretariat Working Group on Energy Statistics

(InterEnerStat) and have been reviewed and supported by the Oslo Group on Energy Statistics and

the United Nations Expert Group on Energy Statistics.23

The definitions of particular products are

followed, whenever necessary, by remarks providing additional clarifications. In cases where a

SIEC category is identical at different levels, i.e. not further subdivided, only the code at the higher

level is shown. The definition naturally applies also to the item at the lower level of the

classification.

0 Coal

This section includes coal, i.e. solid fossil fuel consisting of carbonized vegetal matter and

coal products derived directly or indirectly from the various classes of coal by

carbonization or pyrolysis processes, by the aggregation of finely divided coal or by

chemical reactions with oxidizing agents, including water.

Remark: There are two main categories of primary coal, hard coal (comprising medium-

and high-rank coals) and brown coal (low-rank coals), which can be identified by their

Gross Calorific Value - GCV and the Vitrinite mean Random Reflectance per cent - Rr.

Peat is not included here.

01 Hard coal

Coals with a gross calorific value (moist, ash-free basis) which is not less than 24 MJ/kg, or

which is less than 24 MJ/kg, provided that the coal has a vitrinite mean random reflectance

greater than or equal to 0.6 per cent. Hard coal comprises anthracite and bituminous coals.

011 Anthracite

23 The definitions for nuclear fuel are not in the scope of products discussed by InterEnerStat and have instead been

provided by the International Atomic Energy Agency (IAEA).

35

A high-rank, hard coal with a gross calorific value (moist, ash-free basis) greater than, or

equal to 24 MJ/kg and a Vitrinite mean Random Reflectance greater than or equal to 2.0

per cent.

Remark: It usually has less than 10 per cent volatile matter, a high carbon content (about

86-98 per cent carbon) and is non-agglomerating. Anthracite is mainly used for industrial

and household heat raising.

012 Bituminous coal

A medium-rank hard coal with either a gross calorific value (moist, ash-free basis) not less

than 24 MJ/kg and with a Vitrinite mean Random Reflectance less than 2.0 per cent, or a

gross calorific value (moist, ash-free basis) less than 24 MJ/kg provided that the Vitrinite

mean random reflectance is equal to or greater than 0.6 per cent.

Remark: Bituminous coals are agglomerating and have a higher volatile matter and lower

carbon content than anthracite. They are used for industrial coking and heat raising and

household heat raising.

0121 Coking coal

Bituminous coal that can be used in the production of a coke capable of supporting a blast

furnace charge.

0122 Other bituminous coal

This class includes bituminous coal not included under coking coal.

Remark: This is sometimes referred to as “steam coal”.

02 Brown coal

Coals with a gross calorific value (moist, ash-free basis) less than 24 MJ/ kg and a Vitrinite

mean Random Reflectance less than 0.6 per cent.

Remark: Brown coal comprises sub-bituminous coal and lignite.

021 Sub-bituminous coal

Brown coal with a gross calorific value (moist, ash-free basis) equal to or greater than 20

MJ/kg but less than 24 MJ/kg.

022 Lignite

Brown coal with a gross calorific value (moist, ash-free basis) less than 20 MJ/kg.

03 Coal products

This division includes products derived directly or indirectly from the various classes of

coal by carbonization or pyrolysis processes, or by the aggregation of finely divided coal or

by chemical reactions with oxidising agents, including water.

36

031 Coal coke

This group includes the solid, cellular, infusible material remaining after the carbonization

of certain coals.

Remark: Various cokes are defined according to the type of coal carbonized and their

conditions of carbonization or use: coke oven coke, gas coke, coke breeze and semi cokes.

0311 Coke oven coke

The solid product obtained from carbonization of coking coal at high temperature.

Remark: Coke oven coke is low in moisture, and volatile matter and has the mechanical

strength to support a blast furnace charge. It is used mainly in the iron and steel industry

acting as heat source and chemical agent.

0312 Gas coke

A by-product from the carbonization of bituminous coal for the manufacture of “gas works

gas”.

Remark: Gas coke is used mainly for heating purposes.

0313 Coke breeze

Coke breeze comprises particles of coke of sizes less than 10 mm.

Remark: It is the residue from screening coke. The coke which is screened may be made

from bituminous or brown coals.

0314 Semi cokes

Consists of cokes produced by low temperature carbonization.

Remark: Note that semi cokes may be made from bituminous and brown coals and are used

as a heating fuel.

032 Patent fuel

A composition fuel made by moulding hard coal fines into briquette shapes with the

addition of a binding agent.

Remark: Sometimes referred to as “hard coal briquettes”.

033 Brown coal briquettes (BKB)

A composition fuel made of brown coal produced by briquetting under high pressure with

or without the addition of a binding agent.

Remark: Either sub-bituminous coal or lignite may be used, including dried lignite fines

and dust.

034 Coal tar

The liquid by-product of the carbonization of coal in coke ovens.

37

Remark: Coal tar may be separated by distillation into several liquid products which may

be used for pharmaceutical or wood preservative purposes.

035 Coke oven gas

A gas produced from coke ovens during the manufacture of coke oven coke.

036 Gas works gas (and other manufactured gases for distribution)

This group includes gases obtained from the carbonization or gasification of carbonaceous

material of fossil or biomass origins in Gas Works. The gases comprise: (a) gases obtained

from carbonization or gasification of coals, cokes, biomass or waste; and (b) substitute

natural gas (a methane-rich gas) made from synthesis gas.

Remark: Synthesis gas is a mixture of mainly hydrogen and carbon monoxide obtained by

cracking hydrocarbons with high temperature steam. The hydrocarbons may be taken from

fossil fuels, biofuels or wastes.

037 Recovered gases

Combustible gases of solid carbonaceous origin recovered from manufacturing and

chemical processes of which the principal purpose is other than the production of fuel. This

includes gases containing carbon monoxide resulting from the partial oxidation of (a)

carbon present as coke acting as a reductant in the process, (b) carbon anodes, or (c) carbon

dissolved in iron.

Remark: They may also be referred to as waste or off gases.

0371 Blast furnace gas

The by-product gas of blast furnace operation consisting mainly of nitrogen, carbon dioxide

and carbon monoxide.

Remark: The gas is recovered as it leaves the furnace. Its calorific value arises mainly from

the carbon monoxide produced by the partial combustion of coke and other carbon bearing

products in the blast furnace. It is used to heat blast air and as a fuel in the iron and steel

industry. It may also be used by other nearby industrial plants. Note that where carbonized

biomass (e.g., charcoal or animal meal) is used in blast furnaces, part of the carbon supply

may be considered renewable.

0372 Basic oxygen steel furnace gas

The by-product gas of the production of steel in a basic oxygen furnace. The gas is

recovered as it leaves the furnace.

Remark: The concentration of carbon monoxide in this gas is higher than that in blast

furnace gas. The gas is also known as converter gas, LD gas or BOSF gas.

0373 Other recovered gases

38

Combustible gases of solid carbonaceous origin recovered from manufacturing and

chemical processes not elsewhere defined.

Remark: Examples of fuel gas production from metals and chemicals processing are in the

production of zinc, tin, lead, ferroalloys, phosphorus and silicon carbide.

039 Other coal products

This group includes coal products not elsewhere classified in section 0.


This section comprises peat, a solid formed from the partial decomposition of dead

vegetation under conditions of high humidity and limited air access (initial stage of

coalification) and any products derived from it.

11 Peat

A solid formed from the partial decomposition of dead vegetation under conditions of high

humidity and limited air access (initial stage of coalification). It is available in two forms

for use as a fuel, sod peat and milled peat.

Remark: Milled peat is also made into briquettes for fuel use. Peat is not considered a

renewable resource as its regeneration period is long.

111 Sod peat

Slabs of peat, cut by hand or machine, and dried in the air.

112 Milled peat

Granulated peat produced by special machines.

Remark: Milled peat is used in power stations or for briquette manufacture.

12 Peat products

This division includes products such as peat briquettes derived directly or indirectly from

sod peat and milled peat.

121 Peat briquettes

A fuel comprising of small blocks of dried, highly compressed peat made without a binding

agent.

Remark: Used mainly as a household fuel.

129 Other peat products

Peat products not elsewhere specified such as peat pellets.


A sedimentary rock which contains organic matter in the form of kerogen. Kerogen is a

waxy hydrocarbon-rich material regarded as a precursor of petroleum.

39

Remark: Oil shale may be burned directly or processed by heating to extract shale oil.

While oil shale is classified here, the oils extracted from oil shale and oil sands are included

in SIEC division 45 (Other hydrocarbons).

3 Natural gas

A mixture of gaseous hydrocarbons, primarily methane, but generally also including

ethane, propane and higher hydrocarbons in much smaller amounts and some non-

combustible gases such as nitrogen and carbon dioxide.

Remark: The majority of natural gas is separated from both "non-associated" gas

originating from fields producing hydrocarbons only in gaseous form, and "associated" gas

produced in association with crude oil.

The separation process produces natural gas by removing or reducing the hydrocarbons

other than methane to levels which are acceptable in the marketable gas. The natural gas

liquids (NGL) removed in the process are distributed separately.

Natural gas also includes methane recovered from coal mines (colliery gas) or from coal

seams (coal seam gas) and shale gas. When distributed it may also contain methane from

anaerobic fermentation or the methanation of biomass.

Natural gas may be liquefied (LNG) by reducing its temperature in order to simplify

storage and transportation when production sites are remote from centers of consumption

and pipeline transportation is not economically practicable.

4 Oil

Liquid hydrocarbons of fossil origins comprising (i) crude oil;(ii) liquids extracted from

natural gas (NGL); (iii) fully or partly processed products from the refining of crude oil,

and (iv) functionally similar liquid hydrocarbons and organic chemicals from vegetal or

animal origins.


A mineral oil of fossil origin extracted by conventional means from underground

reservoirs, and comprises liquid or near-liquid hydrocarbons and associated impurities such

as sulphur and metals.

Remark: Conventional crude oil exists in the liquid phase under normal surface temperature

and pressure, and usually flows to the surface under the pressure of the reservoir. This is

termed “conventional” extraction. Crude oil includes condensate from condensate fields

and “field” or “lease” condensate extracted with the crude oil.

The various crude oils may be classified according to their sulphur content (“sweet” or

“sour”) and API gravity (“heavy” or “light”). There are no rigorous specifications for the

classifications but a heavy crude oil may be assumed to have an API gravity of less than 20º

and a sweet crude oil may be assumed to have less than 0.5 per cent sulphur content.

40


Natural gas liquids are a mixture of ethane, propane, butane (normal and iso), (iso) pentane

and a few higher alkanes collectively referred to as pentanes plus.

Remark: NGL are produced in association with oil or natural gas. They are removed in field

facilities or gas separation plants before sale of the gas. All of the components of NGL

except ethane are either liquid at the surface or are liquefied for disposal.

The definition given above is the most commonly used. However, there is some use of

terms based on the vapour pressure of the components which are liquid at the surface or can

be easily liquefied. The three resulting groups are in order of increasing vapour pressure:

condensates, natural gasoline and liquefied petroleum gas.

NGL may be distilled with crude oil in refineries, blended with refined oil products or used

directly. NGL differs from LNG (liquefied natural gas) which is obtained by liquefying

natural gas from which the NGL has been removed.


This division includes refinery feedstocks, i.e. oils or gases from crude oil refining or the

processing of hydrocarbons in the petrochemical industry which are destined for further

processing in the refinery excluding blending. Typical feedstocks include naphthas, middle

distillates, pyrolysis gasoline and heavy oils from vacuum distillation and petrochemical

plants.


Compounds added to or blended with oil products to modify their properties (octane,

cetane, cold properties, etc.).

Remark: Examples are: (a) oxygenates such as alcohols (methanol, ethanol) and ethers

[MTBE (methyl tertiary butyl ether), ETBE (ethyl tertiary butyl ether), TAME (tertiary

amyl methyl ether)]; (b) esters (e.g., rapeseed or dimethylester, etc.); and (c) chemical

compounds (such as TML (tetra ethyl lead), TEL (tetra methyl lead) and detergents). Some

additives/oxygenates may be derived from biomass while others may be of fossil

hydrocarbon origin.


This division includes non-conventional oils and hydrogen. Non-conventional oils refer to

oils obtained by non-conventional production techniques, that is, oils extracted from

reservoirs containing extra heavy oils or oil sands which need heating or treatment (e.g.,

emulsification) in situ before they can be brought to the surface for refining/processing.

They also include oils extracted from oil sands, extra heavy oils, coal and oil shale which

are at, or can be brought to, the surface without treatment and require processing after

mining (ex situ processing). Non-conventional oils may also be produced from natural gas.

41

Remark: The oils may be divided into two groups: (i) oils for transformation (e.g., synthetic

crudes extracted from extra heavy oils, oil sands, coal and oil shale); and (ii) oils for direct

use (e.g., emulsified oils, such as orimulsion and gas-to-liquid (GTL) liquids). Oil sands are

also known as tar sands. Extra heavy oils are also known as bitumen. This is not the oil

product of the same name made from vacuum distillation residue. Although not a

hydrocarbon, hydrogen is included here unless it is a component of another gas.

46 Oil products

Products obtained from crude oil, non-conventional oils or gases from oil and gas fields.

They may be produced through the refining of conventional crude and non-conventional

oils or during the separation of natural gas from gases extracted from oil or gas fields.

461 Refinery gas

Includes a mixture of non-condensable gases, mainly consisting of hydrogen, methane,

ethane and olefins obtained during distillation of crude oil or treatment of oil products (e.g.,

cracking) in refineries or from nearby petrochemical plants.

Remark: It is used mainly as a fuel within the refinery.

462 Ethane

A naturally gaseous straight-chain hydrocarbon (C2H6).

Remark: Ethane is obtained at gas separation plants or from the refining of crude oil. It is a

valuable feedstock for petrochemical manufacture.

463 Liquefied petroleum gases (LPG)

LPG refers to liquefied propane (C3H8) and butane (C4H10) or mixtures of both.

Commercial grades are usually mixtures of the gases with small amounts of propylene,

butylene, isobutene and isobutylene stored under pressure in containers.

Remark: The mixture of propane and butane used varies according to purpose and season of

the year. The gases may be extracted from natural gas at gas separation plants or at plants

re-gasifying imported liquefied natural gas. They are also obtained during the refining of

crude oil. LPG may be used for heating and as a vehicle fuel.

See also the definition for natural gas liquids. Certain oil field practices also use the term

LPG to describe the high vapour pressure components of natural gas liquids.

42

464 Naphtha

Light or medium oils distilling between 30ºC and 210ºC which do not meet the

specification for motor gasoline.

Remark: Different naphthas are distinguished by their density and the content of paraffins,

isoparaffins, olefins, naphthenes and aromatics. The main uses for naphthas are as

feedstock for high octane gasolines and the manufacture of olefins in the petrochemical

industry.

465 Gasolines

Complex mixtures of volatile hydrocarbons distilling between approximately 25°C and

220°C and consisting of compounds in the C4 to C12 range.

Remark: Gasolines may contain blending components of biomass origin, especially

oxygenates (mainly ethers and alcohols), and additives may be used to boost certain

performance features.

4651 Aviation gasoline

Gasoline prepared especially for aviation piston engines with additives which assure

performance under flight conditions. Aviation gasolines are predominantly alkylates

(obtained by combining C4 and C5 isoparaffins with C3, C4 and C5 olefins) with the possible

addition of more aromatic components including toluene. The distillation range is 25ºC to

170ºC.

4652 Motor gasoline

A mixture of some aromatics (e.g., benzene and toluene) and aliphatic hydrocarbons in the

C5 to C12 range. The distillation range is 25ºC to 220ºC.

Remark: Additives are blended to improve octane rating, improve combustion performance,

reduce oxidation during storage, maintain cleanliness of the engine and improve capture of

pollutants by catalytic converters in the exhaust system. Motor gasoline may also contain

biogasoline products when blended.

4653 Gasoline-type jet fuel

Light hydrocarbons for use in aviation turbine power units, distilling between 100ºC and

250ºC. They are obtained by blending kerosene and gasoline or naphtha in such a way that

the aromatic content does not exceed 25 per cent in volume, and the vapour pressure is

between 13.7 kPa and 20.6 kPa.

Remark: Gasoline-type jet fuel is also known as “aviation turbine fuel”.

466 Kerosenes

Mixtures of hydrocarbons in the range C9 to C16 and distilling over the temperature interval

145ºC to 300°C, but not usually above 250ºC and with a flash point above 38ºC.

43

Remark: The chemical compositions of kerosenes depend on the nature of the crude oils

from which they are derived and the refinery processes that they have undergone.

Kerosenes obtained from crude oil by atmospheric distillation are known as straight-run

kerosenes. Such streams may be treated by a variety of processes to produce kerosenes that

are acceptable for blending as jet fuels.

Kerosenes are primarily used as jet fuels. They are also used as domestic heating and

cooking fuels, and as solvents. Kerosenes may include components or additives derived

from biomass when blended.

4661 Kerosene-type jet fuel

A blend of kerosenes suited to flight conditions with particular specifications, such as

freezing point.

Remark: The specifications are set down by a small number of national standards

committees, most notably ASTM (U.S.), MOD (UK), GOST (Russia).

4669 Other kerosene

Kerosene which is used for heating, cooking, lighting, solvents and internal combustion

engines.

Remark: Other names for this product are burning oil, vaporizing oil, power kerosene and

illuminating oil.


This group includes gas oils and heavy gas oils.

4671 Gas oil / Diesel oil

Gas oils are middle distillates, predominantly of carbon number range C11 to C25 and with a

distillation range of 160ºC to 420°C.

Remark: The principal marketed products are fuels for diesel engines (diesel oil), heating

oils and marine fuel.

Gas oils are also used as middle distillate feedstock for the petrochemical industry and as

solvents.

4672 Heavy gas oil

A mixture of predominantly gas oil and fuel oil which distills in the range of approximately

380ºC to 540ºC.

468 Fuel oil

Comprises residual fuel oil and heavy fuel oil. Residual fuel oils have a distillation range of

350ºC to 650ºC and a kinematic viscosity in the range 6 to 55 cSt at 100ºC. Their flash

point is always above 60ºC and their specific gravity is above 0.95. Heavy fuel oil is a

44

general term describing a blended product based on the residues from various refinery

processes.

Remark: Other names commonly used to describe fuel oil include: bunker fuel, bunker C,

fuel oil No. 6, industrial fuel oil, marine fuel oil and black oil.

Residual and heavy fuel oil are used in medium to large industrial plants, marine

applications and power stations in combustion equipment such as boilers, furnaces and

diesel engines. Residual fuel oil is also used as fuel within the refinery.


This group includes oil products not covered in groups 461-468.

4691 White spirit and special boiling point industrial spirits

White spirit and special boiling point (SBP) industrial spirits are refined distillate

intermediates with a distillation in the naphtha/kerosene range. They are mainly used for

non-fuel purposes and sub-divided as: (a) white spirit - an industrial spirit with a flash point

above 30ºC and a distillation range of 135ºC to 200ºC; and (b) industrial spirit (SBP) - light

oils distilling between 30ºC and 200ºC.

Remark: There are seven or eight grades of industrial spirits, depending on the position of

the cut in the distillation range. The grades are defined according to the temperature

difference between the 5 per cent and 90 per cent volume distillation points (which is not

more than 60ºC).

White spirit and industrial spirits are mostly used as thinners and solvents.

4692 Lubricants

Oils, produced from crude oil, for which the principal use is to reduce friction between

sliding surfaces and during metal cutting operations.

Remark: Lubricant base stocks are obtained from vacuum distillates which result from

further distillation of the residue from atmospheric distillation of crude oil. The lubricant

base stocks are then further processed to produce lubricants with the desired properties.

4693 Paraffin waxes

Residues extracted when dewaxing lubricant oils. The waxes have a crystalline structure

which varies in fineness according to the grade, and are colourless, odourless and

translucent, with a melting point above 45ºC.

Remark: Paraffin waxes are also known as “petroleum waxes”.

45

4694 Petroleum coke

Petroleum coke is a black solid obtained mainly by cracking and carbonizing heavy

hydrocarbon oils, tars and pitches. It consists mainly of carbon (90 to 95 per cent) and has a

low ash content.

The two most important categories are "green coke" and "calcined coke".

Green coke (raw coke) is the primary solid carbonization product from high boiling

hydrocarbon fractions obtained at temperatures below 630ºC. It contains 4-15 per cent by

weight of matter that can be released as volatiles during subsequent heat treatment at

temperatures up to approximately 1330ºC.

Calcined coke is a petroleum coke or coal-derived pitch coke obtained by heat treatment of

green coke to about 1330ºC. It will normally have a hydrogen content of less than 0.1 per

cent by weight.

Remark: In many catalytic operations (e.g., catalytic cracking) carbon or catalytic coke is

deposited on the catalyst, thus deactivating it. The catalyst is reactivated by burning off the

coke which is used as a fuel in the refining process. The coke is not recoverable in a

concentrated form.

4695 Bitumen

A solid, semi-solid or viscous hydrocarbon with a colloidal structure, being brown to black

in color.

Remark: It is obtained as a residue in the distillation of crude oil and by vacuum distillation

of oil residues from atmospheric distillation. It should not be confused with the non-

conventional primary extra heavy oils which may also be referred to as bitumen.

In addition to its major use for road pavements, bitumen is also used as an adhesive, a

waterproofing agent for roof coverings and as a binder in the manufacture of patent fuel. It

may also be used for electricity generation in specially designed power plants.

Bitumen is also known in some countries as asphalt, but in others asphalt describes the

mixture of bitumen and stone aggregate used for road pavements.

4699 Other oil products n.e.c.

Products (including partly refined products) from the refining of crude oil and feedstocks

which are not specified above.

Remark: These products will include basic chemicals and organic chemicals destined for

use within the refinery or for sale to or processing in the chemical industry such as

propylene, benzene, toluene and xylene.

5 Biofuels

Fuels derived directly or indirectly from biomass.

46

Remark: Fuels produced from animal fats, by-products and residues obtain their calorific

value indirectly from the plants eaten by the animals.

51 Solid biofuels

Solid fuels derived from biomass.

511 Fuelwood, wood residues and by-products

Fuelwood or firewood (in log, brushwood, pellet or chip form) obtained from natural or

managed forests or isolated trees. Also included are wood residues used as fuel and in

which the original composition of wood is retained.

Remark: Charcoal and black liquor are excluded.

5111 Wood pellets

Wood pellets are a cylindrical product which has been agglomerated from wood residues

by compression with or without the addition of a small quantity of binder. The pellets have

a diameter not exceeding 25 mm and a length not exceeding 45 mm.

5119 Other Fuelwood, wood residues and by-products

This class includes fuelwood, wood residues and by-products, except in the form of wood

pellets.

512 Bagasse

The fuel obtained from the fibre which remains after juice extraction in sugar cane

processing.

513 Animal waste

Excreta of animals, meat and fish residues which, when dry, are used directly as a fuel.

Remark: This excludes waste used in anaerobic fermentation plants. Fuel gases from these

plants are included under biogases.

514 Black liquor

The alkaline-spent liquor obtained from the digesters during the production of sulphate or

soda pulp required for paper manufacture.

Remark: The lignin contained in the liquor burns to release heat when the concentrated

liquor is sprayed into a recovery furnace and heated with hot gases at 900ºC.

Black liquor is used as a fuel in the pulping process.

515 Other vegetal material and residues

Solid primary biofuels not specified elsewhere, including straw, vegetable husks, ground

nut shells, pruning brushwood, olive pomace and other wastes arising from the

maintenance, cropping and processing of plants.

47

516 Charcoal

The solid residue from the carbonization of wood or other vegetal matter through slow

pyrolysis.

52 Liquid biofuels

Liquids derived from biomass and used as fuels.

Remark: Liquid biofuels comprise biogasoline, biodiesels, bio jet kerosene and other liquid

biofuels. They are used for transport, electricity generation and stationary engines.

521 Biogasoline

Liquid fuels derived from biomass and used in spark-ignition internal combustion engines.

Remark: Common examples are: bioethanol (including both hydrous and anhydrous

ethanol); biomethanol; biobutanol; bio ETBE (ethyl-tertio-butyl-ether); and bio MTBE

(methyl-tertio-butyl-ether).

Biogasoline may be blended with petroleum gasoline or used directly in engines. The

blending may take place in refineries or at or near the point of sale.

522 Biodiesels

Liquid biofuels derived from biomass and used in diesel engines.

Remark: Biodiesels obtained by chemical modification are a linear alkyl ester made by

transesterification of vegetable oils or animal fats with methanol. The transesterification

distinguishes biodiesel from straight vegetable and waste oils. Biodiesel has a flash point of

around 150°C and a density of about 0.88 kg/litre. Biological sources of biodiesel include,

but are not limited to, vegetable oils made from canola (rapeseed), soybeans, corn, oil palm,

peanut or sunflower. Some liquid biofuels (straight vegetable oils) may be used without

chemical modification and their use usually requires modification of the engine.

A further category of diesel fuels can be produced by a range of thermal processes

(including for example gasification followed by Fischer-Tropsch synthesis, pyrolysis

followed by hydrogenation, or conversion of sugar to hydrocarbons using microorganisms

(e.g. yeast)). A wide range of biomass feedstocks, including cellulosic materials and algal

biomass, could be used in such processes.

Biodiesels may be blended with petroleum diesel or used directly in diesel engines.

523 Bio jet kerosene

Liquid biofuels derived from biomass and blended with or replacing jet kerosene.

Remark: Bio jet kerosene can be produced by a range of thermal processes, including for

example gasification followed by Fischer-Tropsch synthesis, pyrolysis followed by

hydrogenation, or conversion of sugar to hydrocarbons using microorganisms (e.g. yeast).

48

A wide range of biomass feedstocks, including cellulosic materials and algal biomass could

be used in such processes.

529 Other liquid biofuels

This group includes liquid biofuels not elsewhere specified.

53 Biogases

Gases arising from the anaerobic fermentation of biomass and the gasification of solid

biomass (including biomass in wastes).

Remark: The biogases from anaerobic fermentation are composed principally of methane

and carbon dioxide and comprise landfill gas, sewage sludge gas and other biogases from

anaerobic fermentation.

Biogases can also be produced from thermal processes (by gasification or pyrolysis) of

biomass and are mixtures containing hydrogen and carbon monoxide (usually known as

syngas) along with other components. These gases may be further processed to modify their

composition and can be further processed to produce substitute natural gas.

The gases are divided into two groups according to their production: biogases from

anaerobic fermentation; and biogases from thermal processes.

They are used mainly as a fuel but can be used as a chemical feedstock.


The biogases from anaerobic fermentation are composed principally of methane and carbon

dioxide and comprise landfill gas, sewage sludge gas and other biogases from anaerobic

fermentation.

Explanation: The biogases from anaerobic fermentation are composed principally of

methane and carbon dioxide and include gas produced from a range of wastes and other

biomass materials, including energy crops in anaerobic digesters (including sewage sludge

gas and landfill gas). The gases may be processed to remove the carbon dioxide and other

constituents to produce a methane fuel.

5311 Landfill gas

Biogas from the anaerobic fermentation of organic matter in landfills.

5312 Sewage sludge gas

Biogas from the anaerobic fermentation of waste matter in sewage plants.

5319 Other biogases from anaerobic fermentation

Other biogases from anaerobic fermentation not elsewhere specified.

Remark: Two of the largest sources of these biogases are the fermentation of energy crops

and the fermentation of manure on farms.

49

532 Biogases from thermal processes

Biogases from thermal processes (by gasification or pyrolysis) of biomass.

Remark: Biogases from thermal processes are a mixture containing hydrogen and carbon

monoxide (usually known as syngas) along with other components. These gases may be

further processed to modify their composition and can be further processed to produce

substitute natural gas.

6 Waste

This section includes waste, i.e. materials no longer required by their holders.

Remark: For the purposes of energy statistics, waste refers to the part of these materials that

is incinerated with heat recovery at installations designed for mixed wastes or co-fired with

other fuels.

The heat may be used for heating or electricity generation. Certain wastes are mixtures of

materials of fossil and biomass origin.

61 Industrial waste

Non-renewable waste which is combusted with heat recovery in plants other than those

used for the incineration of municipal waste.

Remark: Examples are used tires, specific residues from the chemical industry and

hazardous wastes from health care. Combustion includes co-firing with other fuels.

The renewable portions of industrial waste combusted with heat recovery are classified

according to the biofuels which best describe them.

62 Municipal waste

Household waste and waste from companies and public services that resembles household

waste and which is collected at installations specifically designed for the disposal of mixed

wastes with recovery of combustible liquids, gases or heat.

Remark: Municipal wastes can be divided into renewable and non-renewable fractions.

7 Electricity

This section includes electricity, i.e. the transfer of energy through the physical phenomena

involving electric charges and their effects when at rest and in motion.

Remark: Electricity can be generated through different processes such as: the conversion of

energy contained in falling or streaming water, wind or waves; the direct conversion of

solar radiation through photovoltaic processes in semiconductor devices (solar cells); or by

the combustion of fuels.

50

8 Heat

This section includes heat, i.e. the energy obtained from the translational, rotational and

vibrational motion of the constituents of matter, as well as changes in its physical state.

Remark: Heat can be produced by different production processes.


This section includes nuclear fuels, including uranium, thorium, plutonium and derived

products that can be used in nuclear reactors as a source of electricity and/or heat, as well as

fuels not elsewhere classified.


This division includes uranium ores and concentrates; natural uranium, uranium enriched in

U 235, plutonium and their compounds; alloys, dispersions (including cermets), ceramic

products and mixtures containing natural uranium, uranium enriched in U 235, plutonium

or compounds of these products; as well as fuel elements (cartridges) of nuclear reactors

(non-irradiated or irradiated).

9101 Uranium ores

This class includes uranium ores and concentrates.

9109 Other uranium and plutonium

This class includes natural uranium, uranium enriched in U 235, plutonium and their

compounds; alloys, dispersions (including cermets), ceramic products and mixtures

containing natural uranium, uranium enriched in U 235, plutonium or compounds of these

products; as well as fuel elements (cartridges) of nuclear reactors (non-irradiated or

irradiated).


This division includes thorium and its compounds; alloys, dispersions (including cermets),

ceramic products and mixtures containing thorium or compounds of thereof; other

radioactive elements and isotopes and compounds (other than uranium, thorium or

plutonium); alloys, dispersions (including cermets), ceramic products and mixtures

containing these elements, isotopes or compounds.


This division includes fuels not elsewhere classified.

51

Chapter 4. Measurement units and conversion factors

A. Introduction

4.1. Energy products are measured in physical units by their mass, volume, and energy

content. The measurement units that are specific to an energy product and employed at the point of

measurement of an energy flow are often referred to as “original” or “natural” units. Coal, for

example, is generally measured by its mass and crude oil by its volume. On the other hand, cross-

fuel tabulations, such as the energy balances, are displayed in a “common” unit to allow

comparison across energy products. These “common” units are usually energy units and require the

conversion from an original unit through the application of an appropriate conversion factor.24

4.2. When different units are used to measure a product, the compiler is left with the task of

converting data which, in the absence of specific information on the products necessary for the

conversion between different units (such as density, gravity and calorific value), may lead to

discrepancies.

4.3. This chapter reviews the measurement units used for energy statistics, explains the

concepts of “original” and “common” units, and presents default conversion factors to use in the

absence of country- or region-specific calorific values.

B. Measurement units

4.4. This section covers “original” or “natural” units, as well as “common” units. It also makes

reference to the International System of Units, often abbreviated as SI from the French “Système

International d’Unités”, which is the modern metric system of measurement established by

international agreement. It provides a logical and interconnected framework for all measurements

in science, industry and commerce (See Box 4.1 for more details on SI.).

4.5. Standardization in the recording and presentation of original units is a primary task of an

energy statistician before quantities can be analysed or compared.

24 A detailed description of units of measure was provided in Energy Statistics: definitions, units of measure and

conversion factors, Studies in Methods, Series F, No. 44, United Nations, New York, 1987, and in the IEA/Eurostat

Energy Statistics Manual, Paris, 2004, Chapter 1, Section 5. The present chapter incorporates and updates material

found in both these publications.

52

Box 4.1: International System of Units

Source: Based on the International Bureau of Weights and Measures (BIPM), http://www.bipm.org/en/si/.

4.6. The base units of SI are a choice of seven well-defined units which by convention are

regarded as dimensionally independent. There are seven base units, each of which represents, at

least in principle, different kinds of physical quantities.

Physical quantity Base unity

length metre

mass kilogram

time second

electric current ampere

thermodynamic temperature kelvin

luminous intensity candela

amount of substance mole

4.7. Derived units of SI are those formed by combining base units according to the algebraic

relations linking the corresponding quantities. They are defined as products of powers of the base

units. When such product includes no numerical factor other than one, the derived units are called

coherent derived units.25

4.8. SI uses a specific set of prefixes known as SI prefixes, which indicate a multiple or

fraction of the unit. These prefixes are:

Factor Name Symbol Factor Name Symbol

101 deca da 10

−1 deci d

102 hecto h 10

−2 centi c

103 kilo k 10

−3 milli m

106 mega M 10

−6 micro µ

109 giga G 10

−9 nano n

1012

tera T 10−12

pico p

1015

peta P 10−15

femto f

25 An example of a coherent derived unit is the Newton (N): 1 N = 1 kg · m/s

2.

The International System of Units (SI) was established by and is defined by the General

Conference on Weights and Measures (CGPM). It is the result of work that started in 1948 to

make recommendations on the establishment of a practical system of units of measurement

suitable for adoption by all signatories to the Convention du Mètre.

In 1954 and 1971, the CGPM adopted as base units the units of the following seven quantities:

length, mass, time, electric current, thermodynamic temperature, luminous intensity and

amount of substance.

In 1960, the CGPM adopted the name Système International d’Unités, with the international

abbreviation SI for this practical system of units and laid down rules for prefixes, derived units,

and the former supplementary units; it thus established a comprehensive specification for units

of measurement.

53

1018

exa E 10−18

atto a

1021

zetta Z 10−21

zepto z

1024

yotta Y 10−24

yocto y

1. Original units

4.9. As mentioned in the paragraph 4.1 above, original units are the units of measurement

employed at the point of measurement of a product flow that are best suited to its physical state

(solid, liquid or gas) and that require the simplest measuring instruments.26

Typical examples are:

mass units (e.g., kilograms or metric tons) for solid fuels;27

volume units (e.g., barrels or litres) or

mass units (metric tons) for oil; and volume units (e.g., cubic metres) for gases. The actual units

used nationally vary according to country and local conditions and reflect historical practice in the

country, sometimes adapted to changing fuel supply conditions.28

4.10. It should be noted that in questionnaires utilized for the collection of energy statistics,

data may be required to be reported in different units from the original/natural unit. For example,

statistics on crude oil and oil products may be requested in a mass or weight basis since the heating

value of oil products by weight displays less variation than the heating value by volume. Statistics

on gases, as well as wastes, can be requested in terajoules or other energy units in order to ensure

comparability, since gases (and wastes) are usually defined on the basis of their production

processes, rather than their chemical composition, and different compositions of the same type of

gas (or waste) entail different energy contents by volume. The collection of statistics on wastes in

an energy unit is based on the measured or inferred heat output used directly for heat raising.

Mass units

4.11. Solid fuels, such as coal and coke, are generally measured in mass units. The SI unit for

mass is the kilogram (kg). Metric tons (tons) are most commonly used to measure coal and their

derivatives. One metric ton corresponds to 1000 kg. Other units of mass used by countries include

the pound (0.4536 kg), short ton (907.185 kg) and long ton (1016.05 kg). Table 1 in Annex B

presents the equivalent factors for converting different mass units.29

Volume units

4.12. Volume units are original units for most liquid and gaseous fuels, as well as some

traditional fuels. The SI unit for volume is the cubic metre which is equivalent to a kilolitre or one

26 See IEA/Eurostat Energy Statistics Manual, Section 5 chapter 1.

27 With some exceptions; for example, fuelwood, which is usually sold in stacks and measured in a local volume unit,

then converted to cubic metres.

28 See IEA/Eurostat Energy Statistics Manual, Annex 3.

29 All conversion factors for pound, short ton and long ton are approximate.

54

thousand litres. Other volume units include the British or Imperial gallon (approximately 4.546

litres), United States gallon (approximately 3.785 litres), the barrel (approximately 159 litres), and

the cubic feet which is also used to measure volumes of gaseous fuels. Given the preference of oil

markets for the barrel as a volume unit, the barrel per day is commonly used within the petroleum

sector to allow direct data comparison across different time frequencies (e.g., monthly versus

annual crude oil production). However, in principle, other units of volume per time can be used for

the same purpose. Table 2 in Annex B shows the equivalent factors to convert volume units.30

Relationship between mass and volume – Specific gravity and density

4.13. The relationship between mass and volume is called density and is defined as mass

divided by volume. Since liquid fuels are measured either by their mass or volume, it is essential to

be able to convert one into the other, and knowing the density allows this:

volume

massDensity =

4.14. Specific gravity is a dimensionless unit defined as the ratio of density of the fuel to the

density of water at a specified temperature. This can also be expressed as the ratio of the mass of a

given volume of fuel, for instance oil, at 15°C to the mass of the same volume of water at that

temperature:

water

fuel

water

fuel

mass

mass

density

densitygravitySpecific ==

4.15. When using the SI or metric system in order to calculate volume, mass is divided by

density. Vice versa, to obtain mass, volume is multiplied by density. When using other

measurement systems, one must consult tables of conversion factors to move between mass and

volume measurements.

4.16. Another measure for expressing the gravity or density of liquid fuels is API gravity, a

standard adopted by the American Petroleum Institute. API gravity is related to specific gravity by

the following formula:

API gravity = 141.5

- 131.5 specific gravity

Energy units

4.17. Energy, heat, work and power are four concepts that are often confused. If force is

exerted on an object and moves it over a distance, work is done, heat is released (under anything

30 All conversion factors for gallons and barrel are approximate.

55

other than unrealistically ideal conditions) and energy is transformed. Energy, heat and work are

three facets of the same concept. Energy is the capacity to do (and often the result of doing) work.

Heat can be a by-product of work, but is also a form of energy. The coherent derived SI unit of

energy, heat and work is the joule (J). The joule is a precise measure of energy and work, defined

as the work done when a constant force of 1 Newton is exerted on a body with mass of 1 gram to

move it a distance of 1 metre. Common multiples of the joule are the megajoule, gigajoule,

terajoule and petajoule.

4.18. Other units include: the kilogram calorie in the metric system, or kilocalorie, (kcal) or one

of its multiples; the British thermal unit (Btu) or one of its multiples; ton of coal equivalent (tce),

ton of oil equivalent (toe); and the kilowatt hour (kWh).

4.19. The International Steam Table Calorie (IT calorie) was originally defined as 1/860

international watt-hour, but was later defined exactly as 4.1868 joules.31

This is the definition of

the calorie used in the conversion tables in the annex to this chapter. The kilocalorie and the

teracalorie are multiples of the calorie that are commonly used in the measurement of energy

commodities. In the context of IRES, these are based on the IT calorie. Other definitions of the

calorie include the gram calorie, defined by the amount of heat required to raise the temperature of

one gram of water 1°C from a reference temperature. With a reference temperature of 14.5°C, the

gram calorie equals 4.1855 joules. 32

4.20. The British thermal unit is a measure of heat and is equal to the amount of heat required

to raise the temperature of 1 pound of water at 60°F by 1°F.33

Its most used multiples are the therm

(105 Btu) and the quad (10

15 Btu). The internationally agreed value for the Btu is currently 1055.06

joules.

4.21. In the past, when coal was the principal commercial fuel, the ton of coal equivalent (tce)

was commonly used as an energy unit. However, with the increasing importance of oil it has been

replaced by the ton of oil equivalent (toe). The toe is now defined as 41.868 gigajoules, whereas

the tce equals 29.3076 gigajoules. Generally, it should not be assumed that one ton of coal contains

one tce or that one ton of oil contains one toe of energy content since there is a wide spread in

calorific values among various types of coals, crude oils and petroleum products.34

4.22. Power is the rate at which work is done (or heat released, or energy converted). The rate

of one joule per second is called a watt. As an example, a light bulb might draw 100 joules of

electricity per second to emit light and heat (both forms of energy). This light bulb would then

draw the power of 100 watts.

31 Defined at the Fifth International Conference on the Properties of Steam (London, July 1956).

32 Other reference temperatures are also encountered, which leads to different values for the gram calorie.

33 °F denotes degrees Fahrenheit.

34 See Chapter 4, Section C.

56

4.23. The above definition of watt leads to another commonly used measure of energy, the

kilowatt hour (kWh), which refers to the energy equivalent of 1000 watt (joules per second) over a

one-hour period. Thus, 1 kilowatt-hour equals 3.6x106 joules.

4.24. Electricity is usually measured in kWh. This allows one to perceive the electrical energy

in terms of the time an appliance of a specified wattage takes to “consume” this energy. Heat

quantities, on the other hand, are usually measured in calories or joules.

4.25. Table 3 in Annex B shows the conversion factors between several energy units.

2. Common units

4.26. Since the original units in which energy products are measured vary (e.g., metric tons,

barrels, kilowatt hours, therm, calories, joules, cubic metres), quantities of energy products need to

be converted into a common unit to allow comparisons of fuel quantities and estimate

transformation efficiencies. The conversion from different units to a common unit may require

specific conversion factors for each product.35

4.27. The only energy unit in the International System of Units is the joule and it is usually

used in energy statistics as a common unit, although other energy units are sometimes also applied

(e.g., toe, GWh, Btu, calories, etc.). The use of the joule as a common unit is recommended.

4.28. It is further recommended that national and international agencies in charge of energy

statistics and any other organizations that advise them or undertake work for them, always clearly

define the measurement units, as well as the common units used for the presentational purposes in

various publications and in electronically disseminated data. The conversion factors and the

methods used to convert original physical units into the chosen common unit or units should be

described in energy statistics metadata and be readily accessible to users. In addition, it should be

made clear whether energy units are defined on a gross or net calorific basis (See Section C below

for details.).

C. Calorific values

4.29. Calorific values or heating values of a fuel express the heat obtained from one unit of the

fuel. They are necessary for the compilation of overall energy balances where the original units in

which the fuels are measured are converted into a common unit of measurement. Even though

calorific values are often considered in the context of the preparation of energy balances, they have

a wider application in the preparation of any tables designed to show energy in an aggregated form

or in the preparation of inter-fuel comparative analyses.

35 For example, the factor to convert from m

3 to TJ will be different for different types of gaseous or liquid fuels.

However, the factor to convert from kWh to TJ is the same for all products.

57

4.30. Calorific values are obtained by measurements in a laboratory specializing in fuel quality

determination. They should preferably be in terms of joules (or any of its multiples) per original

unit, for example gigajoule/metric ton (GJ/t) or gigajoule/cubic metre (GJ/m3). Major fuel

producers (mining companies, refineries, etc.) normally measure the calorific value and other

qualities of the fuels they produce. A calorific value is a conversion factor, in the sense that it can

be used to convert mass or volume quantities into energy content.

4.31. There are two main issues with regards to calorific values that an energy compiler should

pay attention to: the first one refers to whether they are measured gross or net of the latent heat

(that is the heat necessary to evaporate the water formed during combustion and the water

previously present in the fuel in the form of moisture); and the second one is related to whether the

calorific value used refers to the specific product-flow-country situation or it refers to a default

value. These two issues are presented in detail in the next two sections.

1. Gross and net calorific/heating values

4.32. Calorific values can be expressed on a gross and net basis. The gross calorific value

(GCV), or high heat value, measures the total (maximum) amount of heat that is produced by

combustion. However, part of this heat will be locked up in the latent heat of evaporation of any

water present in the fuel before combustion (moisture) or generated in the combustion process. The

latter comes from the combination of hydrogen present in the fuel with the oxidant oxygen (O2)

present in the air to form H2O. This combination itself releases heat, but this heat is partly used in

the evaporation of the generated water.

4.33. The net calorific value (NCV), or low heat value, excludes the latent heat. The NCV is

that amount of heat from the combustion process that is actually available in practice for capture

and use. The higher the moisture of a fuel or its hydrogen content, the greater is the difference

between GCV and NCV. For some fuels with very little or no hydrogen content (e.g., some types

of coke, blast furnace gas) this difference is negligible. In terms of magnitude, the difference

between gross and net calorific values of fossil fuels (coal, oil, oil products and gas) is typically

less than 10 per cent, while that of biomass energy (fuelwood, bagasse) is usually more than 10 per

cent. Examples of differences between gross and net calorific values are presented for selected

energy products in Table 4 of Annex B. It should be noted that the technology used to burn a fuel

can also play a role in determining the NCV of that fuel for instance, depending on how much of

the latent heat it can recover from the exhaust gases.

4.34. It is recommended that, when expressing the energy content of energy products in terms

of a common energy unit, net calorific values (NCVs) be used in preference to gross calorific

values (GCVs). In other words, the heat required to evaporate moisture, which is present in all

fuels and is also produced in the combustion process, should not be treated as part of a fuel's

energy providing capability. In particular, NCVs are to be preferred over GCVs when building an

energy balance, since most current technologies are still not able to recover the latent heat, which

would thus not be treated as part of a fuel's energy providing capability (see Chapter 8 for further

58

discussion).36

However, where available, it is strongly encouraged to report both gross and net

calorific values.

2. Default vs. specific calorific values

4.35. Energy products with exactly the same chemical composition will carry the same energy

content. In practice, however, there are variations in the composition of energy products and

consequently, their calorific values can vary. For example, "premium" gasoline may have slightly

different chemical formulations (and therefore a different energy content) than “regular” gasoline;

natural gas may contain variations in the proportions of ethane and methane; liquefied petroleum

gas (LPG) may in fact be solely propane or solely butane or any combination of the two. Only

those products which are single energy compounds, such as "pure" methane or "pure" ethane, and

electricity, have precise and unalterable energy contents.

4.36. Default calorific values refer to the energy content of fuels with specific characteristics

that are generally applicable to all circumstances (different countries, different flows, etc.). They

are used as default values when specific calorific values are not available. Specific calorific values,

on the other hand, are based on the specificity of the fuel in question and are measurable from the

original data source. They are particularly important for fuels which present different qualities:

coal, for example, displays a range of quality which makes it suitable for different uses. The

respective calorific values are thus specific to the fuel and flow in question. However, in using

many different specific calorific values, caution should be applied to ensure consistency between

the energy content on the supply side and on the consumption side for a particular country and

year.

4.37. Often there is a problem in energy statistics as the product produced may not be identical

in composition to the product in subsequent processes, even though it is referred to by the same

name. Natural gas can be enriched with oil products, for example, to meet market specifications.

Motor gasoline can be blended with ethanol and sold as motor gasoline, and depending on the

country practice, this may be recorded as consumption of only motor gasoline or as consumption of

motor gasoline and the blending agent. In this case, flow-specific calorific values would allow for a

more accurate energy balance.

4.38. It is recommended that countries collect data in original units together with data on

specific calorific values. A country-specific calorific value is generally calculated as a weighted

average of all the calorific values collected for the energy product in question (see next section).

For some products (e.g., coal and crude oil), different calorific values may be needed for

production, imports, exports and several major uses. Default calorific values should only be used

36 A number of countries are currently able to recuperate a significant part of the latent heat, and thus the use of gross

calorific values may reflect more appropriately their circumstances.

59

as a last resort in the absence of specific values, acknowledging that this simplification will affect

the precision of the published figures.

4.39. It is further recommended that metadata be provided on the methods used in all

calculations and conversions undertaken to arrive at the disseminated data in order to ensure

transparency and clarity and to enable comparability. In particular, this would include the

conversion factors between original and presented units, whether they are on a gross or net

calorific basis, and any use of default values.

3. How to calculate average calorific values

4.40. The calculation of calorific values is not straightforward. There are two levels involved in

the calculation of calorific values. The first is the actual measurement of the heating value of an

energy product. This is done in laboratories specializing in fuel quality determination. In general,

major fuel producers (i.e., mining companies, refineries, etc.) measure the quality of the energy

product they produce as this may affect its price and specification. This type of calculation thus

pertains to specialists and it is not covered in IRES: the calorific values are assumed to be available

from the data providers (generally companies producing energy).

4.41. The second level in the calculation of the calorific values pertains more to the compilers

of energy statistics as it involves the aggregation of different qualities of a fuel. Coals produced at

different mines, for example, often have different qualities. The quality of imported coal may vary

according to the origin of the flow. Similarly, the quality of consumed coal may also differ: the

case, for example, of imported steam coal for electricity generation, and home-produced lignite for

household consumption. Thus, in the preparation of energy balances and in the comparison of the

energy content of energy products, it is necessary to take into account the different qualities of the

products themselves.

4.42. In general, in order to aggregate different qualities of an energy product, it is necessary to

calculate the average calorific value. Consider, for example, the case where the production of

lignite comes from two different mines in a country: mine A produces 1.5 thousand metric tons of

lignite with a net calorific value of 10.28 TJ/thousand tons, while mine B produces 2.5 thousand

metric tons of lignite with a net calorific value of 12.10 TJ/thousand tons. The average net calorific

value of the total production of lignite of the country is calculated as a weighted average of the

calorific values from the two mines with their production as weights. The calculations are shown in

the example below:

Production

(1000 metric

tons)

Calorific value

(TJ/1000 metric

tons)

Average calorific value

(TJ/1000 metric tons)

Production

(TJ)

Mine A 1.5 10.28 15.42

Mine B 2.5 12.1 30.25

Total 4 42.115.25.1

10.125.228.105.1=

+

×+×=

67.45442.11 =×=

60

4.43. The average calorific value calculated as above corresponds to the country-specific

calorific values that are generally collected by international organizations in their energy

questionnaires and are reported in the disseminated data.

4.44. Since calorific values may change according to the type of flow (e.g., production,

imports, exports, consumption by different types of users, etc.), countries are encouraged to

collect calorific values at least on production, imports and exports.

4. Default calorific values

4.45. The default calorific values are provided in Table 4.1 as a reference for countries when no

specific calorific values are available. The default calorific values presented below are those used

in the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC 2006). For a number

of products, no calorific values are available in the 2006 IPCC Guidelines and thus no value is

reported in the table below.

Table 4.1: Default net calorific values for energy products

Net Calorific Values

(GJ/metric ton)

Range

SIEC Headings Default value

Lower

value

Upper

value

0 Coal

01 Hard coal

011 0110 Anthracite 26.7 21.6 32.2

012 Bituminous coal

0121 Coking coal 28.2 24.0 31.0

0129 Other bituminous coal 25.8 19.9 30.5

02 Brown coal

021 0210 Sub-bituminous coal 18.9 11.5 26.0

022 0220 Lignite 11.9 5.5 21.6

03 Coal products

031 Coal coke

0311 Coke oven coke 28.2 25.1 30.2

0312 Gas coke 28.2 25.1 30.2

0313 Coke breeze

0314 Semi cokes 28.2 25.1 30.2

032 0320 Patent fuel 20.7 15.1 32.0

033 0330 Brown coal briquettes (BKB) 20.7 15.1 32.0

034 0340 Coal tar 28.0 14.1 55.0

035 0350 Coke oven gas 38.7 19.6 77.0

036 0360 Gas works gas (and other manuf. gases for distribution) 38.7 19.6 77.0

037 Recovered gases

0371 Blast furnace gas 2.47 1.20 5.00

0372 Basic oxygen steel furnace gas 7.06 3.80 15.00

0379 Other recovered gases

039 0390 Other coal products


11 Peat

111 1110 Sod peat 9.76 7.80 12.5

112 1120 Milled peat 9.76 7.80 12.5

12 Peat products

121 1210 Peat briquettes 9.76 7.80 12.5

61

129 1290 Other peat products 9.76 7.80 12.5



200 2000 Oil shale / oil sands 8.9 7.1 11.1

3 Natural gas

30 Natural gas

300 3000 Natural gas 48.0a 46.5 50.4

4 Oil


410 4100 Conventional crude oil 42.3 40.1 44.8


420 4200 Natural gas liquids (NGL) 44.2 40.9 46.9


430 4300 Refinery feedstocks 43.0 36.3 46.4


440 4400 Additives and oxygenates


450 4500 Other hydrocarbons

46 Oil products

461 4610 Refinery gas 49.5 47.5 50.6

462 4620 Ethane 46.4 44.9 48.8

463 4630 Liquefied petroleum gases (LPG) 47.3 44.8 52.2

464 4640 Naphtha 44.5 41.8 46.5

465 Gasolines

4651 Aviation gasoline 44.3 42.5 44.8

4652 Motor gasoline 44.3 42.5 44.8

4653 Gasoline-type jet fuel 44.3 42.5 44.8

466 Kerosenes

4661 Kerosene-type jet fuel 44.1 42.0 45.0

4669 Other kerosene 43.8 42.4 45.2


4671 Gas oil / Diesel oil 43.0 41.4 43.3

4672 Heavy gas oil

468 4680 Fuel oil 40.4 39.8 41.7


4691 White spirit and special boiling point industrial spirits 40.2 33.7 48.2

4692 Lubricants 40.2 33.5 42.3

4693 Paraffin waxes 40.2 33.7 48.2

4694 Petroleum coke 32.5 29.7 41.9

4695 Bitumen 40.2 33.5 41.2

4699 Other oil products n.e.c. 40.2 33.7 48.2

5 Biofuels

51 Solid biofuels

511 Fuelwood, wood residues and by-products 15.6 7.9 31.0

5111 Wood pellets 17.3d

5119 Other Fuelwood, wood residues and by-products 13.9d

512 5120 Bagasse

513 5130 Animal waste

514 5140 Black liquor 11.8 5.9 23.0

515 5150 Other vegetal material and residues

516 5160 Charcoal 29.5 14.9 58.0

52 Liquid biofuels

521 5210 Biogasoline 26.8 b

13.6 54.0

522 5220 Biodiesels 36.8 b

13.6 54.0

523 5230 Bio jet kerosene

529 5290 Other liquid biofuels 27.4 13.8 54.0

53 Biogases


5311 Landfill gas 50.4 25.4 100.0

5312 Sewage sludge gas 50.4 25.4 100.0

5319 Other biogases from anaerobic fermentation 50.4 25.4 100.0

532 5320 Biogases from thermal processes

62

6 Waste

61 Industrial waste

610 6100 Industrial waste

62 Municipal waste

620 6200 Municipal waste 11.6 / 10.0c 6.8 / 7.0 c 18.0 / 18.0 b

7 Electricity

70 Electricity

700 7000 Electricity

8 Heat

80 Heat

800 8000 Heat




9101 Uranium ores

9109 Other uranium and plutonium


920 9200 Other nuclear fuels


990 9900 Other fuels n.e.c.

a Whereas the values provided in this table are presented in units of energy per mass, the calorific values for natural gas

are often expressed in units of energy per volume. For example, UN (1988) provides a NCV of 39.02 GJ/thousand m3

under standard conditions for natural gas. It should be noted, however, that this number is not derived from the value

presented in this table.

b Source: IEA.

c Values refer to the biomass / non-biomass fraction, respectively.

d Source: Austrian Energy Agency.

Fuelwood

4.46. In rural areas of many developing countries, the principal source of energy for cooking

and heating is fuelwood, but statistics on fuelwood in general are poor. This is due largely to the

fact that fuelwood is in great part produced by households for their own use and/or traded in the

informal sector.

4.47. There is a large variety of wood species and a large variability of moisture and ash

content in wood products which highly affect the calorific value of the product. Countries are

therefore encouraged to identify typical fuelwood mixes and average water content and to establish

country specific conversion factors between volume and mass. Guidelines for the measurement of

fuelwood and the determination of calorific values are provided below.

4.48. Fuelwood can be measured by either volume or weight. If it is measured by volume, it

can be either stacked volume or solid volume. Measures of stacked fuelwood are the stere or

stacked cubic metre and the cord (128 stacked cubic feet). Solid volume is obtained by the water

displacement method, that is the volume of water displaced if the quantity of fuelwood were to be

completely submerged. One advantage of measurement by volume is the relatively small influence

of the moisture content of the wood on the measurement results. The weight of fuelwood is highly

dependent on moisture content and this is true for all biomass. The more water per unit weight, the

63

less fuelwood. Therefore, it is important that the moisture content be accurately specified when

fuelwood is measured by weight.

4.49. There are two ways of measuring moisture content (mc). They are the so-called "dry

basis" and "wet basis" and are defined below:

Dry basis: 100dry weight

dry weightwet weight%mc x

−=

Wet basis: 100wet weight

dry weightwet weight%mc x

−=

4.50. When biomass is very wet there is a large difference between the two moisture contents

(e.g., 100 per cent mc dry basis = 50 per cent mc wet basis), but when the biomass is air-dry the

difference is small (15 per cent mc dry basis = 13 per cent mc wet basis). It is important to state on

which basis the moisture content is measured. In most, but not all cases, fuelwood moisture is

measured on a dry basis.

4.51. Another important determinant of the energy content of fuelwood is ash content. While

the ash content of fuelwood is generally around one per cent, some species can register an ash

content of up to four per cent. This affects the energy value of the wood since the substances that

form the ashes generally have no energy value. Thus wood with four per cent ash content will have

three per cent less energy content than wood with one percent ash content.

4.52. The default calorific values for fuelwood (converting from mass units to energy units) are

presented in Table 4.2. The table shows how the calorific values vary with different moisture

content of green wood, air-dried wood and oven-dried wood.

Table 4.2: Influence of moisture content on net calorific values of standard fuelwood

(Wood with one per cent ash content)

Percentage moisture

content

Kilocalories

per kilogram

Btus

per pound

Megajoules per

kilogram

Dry

basis

Wet

basis

Green wood 160 62 1360 2450 5.7

140 59 1530 2750 6.4

120 55 1720 3100 7.2

100 50 1960 3530 8.2

80 45 2220 4000 9.3

70 41 2390 4300 10.0

Air-dried wood 60 38 2580 4640 10.8

50 a 33 a 2790 5030 11.7

40 29 3030 5460 12.7

64

30 23 3300 5930 13.8

25 b 20 b 3460 6230 14.5

20 17 3630 6530 15.2

15 13 3820 6880 16.0

Oven-dried wood 10 9 4010 7220 16.8

5 5 4230 7610 17.7

0 0 4470 8040 18.7

Sources: UN (1987). a Average of as-received fuelwood on cordwood basis (4-foot lengths). b Average of logged fuelwood.

4.53. When fuelwood is collected in volume units, a conversion factor has to be used to obtain

mass units. Table 4.3 shows the conversion factors for going from volume to mass units. Table 5 in

Annex B shows how the different moisture contents of fuelwood affect the conversion factors

between cubic metres and metric tons.

Table 4.3: Conversion table for fuelwood

(Wood with 25 per cent moisture content)

Fuelwood

Metric tons

per solid cubic

metre

Metric tons per

cord

Stacked cubic

metres (stere)

per metric ton

General 0.707 1.71 2.12

Coniferous 0.570 1.38 2.63

Non-Coniferous 0.742 1.79 2.02

Source: UNECE/FAO (2010)37

Note: Cubic metre is measured under bark at 25 per cent moisture content (dry basis).

Weight includes bark. The “General” data is weighted on 20 per cent coniferous and 80 per cent non-coniferous wood.

Charcoal

4.54. The amount of biomass (usually fuelwood) necessary to yield a given quantity of charcoal

depends mostly on three factors: density, moisture content and the means of charcoal production.

4.55. The principal factor in determining the yield of charcoal from fuelwood is the parent

wood density, since the weight of charcoal can vary by a factor of 2 for equal volumes. The

moisture content of the wood also has an appreciable effect on yields as the drier the wood, the

greater the yield. The third determinant factor is the means of charcoal production. Charcoal is

produced in earth-covered pits, oil drums, brick or steel kilns and retorts. The less sophisticated

means of production generally involve loss of powdered charcoal (fines), incomplete carbonization

of the fuelwood and combustion of part of the charcoal product, resulting in lower yields.

37 See Forest Products Conversion Factors for the UNECE Region, Geneva Timber and Forest Discussion Paper 49.

UNECE/FAO, 2010 (http://www.unece.org/fileadmin/DAM/timber/publications/DP-49.pdf), updated in 2015.

65

4.56. There is always an amount of powdered charcoal produced in the manufacture and

transport of charcoal. If powdered charcoal undergoes briquetting, then the weight of the briquettes

may be 50-100 per cent higher per given volume of un-powdered charcoal due to greater density.

4.57. The three variables which affect the energy value of charcoal are: moisture content, ash

content and degree of carbonization. The average moisture content of charcoal is 5 per cent. The

average ash content of wood charcoal is 4 per cent, while that of charcoal produced from woody

crop residues, such as coffee shrubs, is near 20 per cent. With the assumption of complete

carbonization, the average energy value of wood charcoal with 4 per cent ash content and 5 per

cent moisture content is approximately 30.8 MJ/kg. The average energy value of crop residue

charcoal with 20 per cent ash content and 5 per cent moisture content is 25.7 MJ/kg.

4.58. Two tables pertaining to charcoal production are provided in Annex B. In particular,

Table 6 illustrates the effect of parent wood density and moisture content on charcoal yield.

Table 7 provides conversion factors for the production of charcoal by the various kilns for selected

percentages of wood moisture content. It assumes some standard hardwood as input to the process.

Vegetal and animal wastes

4.59. Agricultural wastes and waste products from food processing are used to replace woody

biomass in fuelwood deficient areas. These waste products can be burned as fuels to fulfil heating

or cooking requirements.

4.60. There are two important determinants of the energy value of non-woody plant biomass:

moisture content and ash content. While the ash content of wood is generally around 1 per cent,

that of crop residues can vary from 3 per cent to over 20 per cent, and this affects the energy value.

Generally, the substances that form the ashes have no energy value. Thus, biomass with 20 percent

ash content will have 19 percent less energy than a similar substance with 1 per cent ash content.

Data for these potential sources of energy are rarely collected directly but derived from crop/waste

or end-product/waste ratios. Due to this wide variability in composition in ash and moisture

content of general animal and vegetal wastes across countries, it is recommended that these

products be reported to international organizations in an energy unit (preferably TJ) rather than

their natural units. National authorities are, in general, able to assess and determine the energy

content of these wastes. Alternatively, measuring the energy content can be accomplished by

measuring the heat or electricity output of transformation devices and applying standard efficiency

factors.

4.61. Given the importance of the use of bagasse, the fibrous cane residue from the production

of sugar from sugar cane, possible estimation procedures are outlined for this case below. Also,

singling out this specific vegetal waste allows the reporting of quantities to international

organizations in its natural unit (weight basis), since its composition does not allow much

variation. This has been done by international organizations that treat bagasse separately from

ordinary vegetal waste. Bagasse is used as a fuel mostly for the sugar industry's own energy needs

(at times, excess electricity is also fed into the public grid) in many sugar-producing countries. The

66

availability of fuel bagasse can be estimated based on either data on the input of sugar cane into

sugar mills, or production data on centrifugal cane sugar.

4.62. Method (a): Studies based on experiences in Central American countries found that the

yield of fuel bagasse is approximately 280 kilograms per metric ton of sugar cane processed.

Assuming a 50 per cent moisture content at the time of use, 1 metric ton of bagasse yields 7.72 GJ.

The energy values for bagasse corresponding to 1 metric ton of processed sugar cane are, therefore,

as follows:

2.16 GJ = 0.516 Gcal = 0.074 tce = 0.051 toe

4.63. Method (b): Based on observations, the Economic Commission for Latin America and the

Caribbean (ECLAC) proposed the use of 3.26 kg bagasse yield per kilogram of centrifugal sugar

produced. Calorific equivalents for bagasse corresponding to the production of 1 metric ton of

sugar are as follows:

25.2 GJ = 6 Gcal = 0.86 tce = 0.59 toe

4.64. Animal waste or dung is another important by-product of the agricultural sector. It can be

dried and burned directly as a fuel for space heating, cooking or crop drying. When used as an

input to biogas digestors, the outputs are gas for cooking, heating and lighting, and a solid residue

for use as fertilizer. Another possibility is to use the animal waste as a feedstock to produce

biodiesel. It can also be spread with no or minimal treatment in the fields as fertilizer. Table 8 of

Annex B presents various animal and vegetal wastes and indicates the approximate calorific values

recoverable from them when used as fuels.

5. Units recommended for dissemination

4.65. No specific measurement unit is recommended for national data collection, thus allowing

countries to choose the units most suitable for their circumstances. However, based on common

practices, certain units are recommended for data dissemination. If necessary, countries may use

other units, as long as appropriate conversion factors are provided.

4.66. For each main category of energy products, the recommended unit for dissemination is

provided in Table 4.4. Where there is no special mention, the unit applies to primary as well as to

secondary energy products.

Table 4.4: Recommended units for dissemination

Energy products Dimension Unit

Solid fossil fuels Mass Thousand metric tons

Liquid fossil fuels Mass Thousand metric tons

(Liquid) Biofuels Mass/Volume Thousand metric tons/ Thousand cubic metres

Gases Energy Terajoules

Wastes Energy Terajoules

Fuelwood Volume/ Energy Thousand cubic metres/ Terajoules

67

Charcoal Mass Thousand metric tons

Electricity Energy GWh

Heat Energy Terajoules

Common unit (e.g., balances) Energy Terajoules

Electricity installed capacity Power MW

Refinery capacity Mass/time Thousand metric tons/year

4.67. It is recommended that countries report to international organizations both physical

quantities of fuels and their country-specific (and where necessary flow-specific) calorific values.

In the case of waste that is well-defined by its constitution, rather than only by the process from

which it was generated, it can be assumed that there would not be great variation in specific

calorific values. Therefore, data can be reported on a weight basis (thousand metric tons). Even so,

the specific calorific values should be provided if they are available.

68

Chapter 5. Energy Flows

A. Introduction

5.1. The objective of this chapter is to describe energy flows and the main groups of economic

units that are relevant for the collection of data on such flows. In particular, this chapter provides a

description of energy industries and energy consumers and presents a cross-classification of energy

consumers and energy uses. The concepts and definitions introduced in this chapter complement

the concepts, definitions and classifications introduced in Chapters 3 and 4 and provide a

foundation for the identification of data items, the formulation of data collection and data

compilation strategies and the compilation of energy balance which are described in Chapters 6, 7

and 8.

B. Concept of energy flows

5.2. In the context of basic energy statistics and energy balances, the term “energy flow” refers

to the production, import, export, bunkering, stock changes, transformation, energy use by energy

industries, losses during the transformation, and final consumption of energy products within the

territory of reference for which these statistics are compiled.38

This territory generally corresponds

to the national territory; however, it can also refer to an administrative region at sub-national level

or even to a group of countries. The term “rest of the world” is used here to denote all

areas/territories outside the reference territory.

5.3. The first appearance of an energy product in the territory of reference is either through its

production or by being imported. Whereas some energy products may be used directly in the form

they were captured from the environment, many energy products undergo some sort of

transformation before final consumption. This is the case, for example, with the processing of

crude oil in petroleum refineries, where the oil is transformed into a range of products that are

useful for specific purposes (e.g., gasoline for transportation).

5.4. Once produced and/or transformed, energy products can be: (a) exported to other territories;

(b) stored for later use (entering into stock); (c) used for refuelling of ships and airplanes engaged

in international voyages (international bunkering); (d) used by the energy industries themselves;

and/or (e) delivered for final consumption.

38It is acknowledged that there are additional energy flows that are relevant for the compilation of energy accounts

such as, for example, the use of energy products abroad by resident units and the use of energy products inland by non-

resident units.

69

5.5. The final consumption of energy products consists of (a) final energy consumption, i.e.

deliveries of energy products to the users located in the territory of reference for their energy

needs, such as for heat raising, transportation and electricity, and (b) non-energy use, i.e. deliveries

of energy products for use as chemical feedstocks or as raw materials (see para. 5.21 for details).

5.6. For energy policy and analytical purposes, the final energy consumption is further

disaggregated according to type of economic activity, while the use of energy products for the

purpose of transport is identified independently from the economic sector in which they were

consumed.

5.7. A diagram representing the main energy flows is presented in Figure 5.1 below, while their

definitions are provided in the subsequent sections of the chapter.

Figure 5.1: Diagram of the main energy flows

5.8. Energy flows and economic units. Energy flows are generated by the activities of various

economic units. These flows are defined in section C below. Depending on their role in the flow of

energy through the economy, the economic units can be categorized as energy industries, other

energy producers and energy consumers. This will be presented in sections D, E and F,

respectively.

C. Definition of main energy flows

5.9. This section provides definitions and explanations of the main energy flows. Note that the

definitions presented here are the result of the work of the Intersecretariat Working Group on

70

Energy Statistics (InterEnerStat) and have been reviewed and supported by the Oslo Group on

Energy Statistics and the United Nations Expert Group on Energy Statistics. It is recommended

that countries follow these definitions in their official energy statistics as closely as possible. Any

deviations should be reflected in countries’ energy metadata.

5.10. Production is defined as the capture, extraction or manufacture of fuels or energy in forms

that are ready for general use. In energy statistics, two types of production are distinguished,

primary and secondary. Primary production is the capture or extraction of fuels or energy from

natural energy flows, the biosphere and natural reserves of fossil fuels within the national territory

in a form suitable for use. Inert matter removed from the extracted fuels and quantities reinjected,

flared or vented are not included. The resulting products are referred to as “primary” products.

Secondary production is the manufacture of energy products through the process of

transformation of other fuels or energy, whether primary or secondary. The quantities of secondary

fuels reported as production include quantities lost through venting and flaring during and after

production. In this manner, the mass, energy and carbon within the primary source(s) from which

the fuels are manufactured may be balanced against the secondary fuels produced. Fuels, electricity

and heat produced are usually sold but may be partly or entirely consumed by the producer.

5.11. Imports of energy products comprise all fuel and other energy products entering the

national territory. Goods simply being transported through a country (goods in transit) and goods

temporarily admitted are excluded, while re-imports (i.e. domestic goods exported but

subsequently readmitted) are included. The bunkering of fuel outside the reference territory by

national merchant ships and civil aircraft engaged in international travel is also excluded from

imports.39

Note that the “country of origin” of energy products should be recorded, where possible,

as the country from which goods were imported, but not a transit country.

5.12. Exports of energy products comprise all fuel and other energy products leaving the

national territory. Goods simply being transported through a country (goods in transit) and goods

temporarily withdrawn are excluded, while re-exports (i.e. foreign goods exported in the same state

as previously imported) are included. Also excluded are quantities of fuels delivered for use by

merchant ships (including passenger ships) and civil aircraft of all nationalities during international

transport of goods and passengers.40

Note that the “country of destination” of energy products (i.e.

the country of the last known destination as it is known at the time of exportation) should be

recorded as a country to which these products are exported to.

5.13. It should be noted that the definitions of imports and exports used in energy statistics are

those adopted by international merchandise trade statistics for a system of recording known as the

“general trade system”, that is, all energy products entering and leaving the national territory of a

39 Such fuels should be classified as “international marine bunkers” or “international aviation bunkers”, respectively, in

the country where such bunkering is carried out (see paragraphs 5.14, 5.15).

40 These quantities are recorded as “international marine bunkers” and “aviation bunkers”, respectively.

71

country and which add to or subtract from the stock of material resources of a country are recorded

as energy imports and exports,41

except for the bunkering of international fleet which is excluded

from trade figures.42

It should also be noted that, in energy balances, imports and exports exclude

nuclear fuels as these are not within the scope of energy balances (see also Chapter 8).

5.14. International Marine Bunkers are quantities of fuels delivered to merchant ships

(including passenger ships) of any nationality for consumption during international voyages

transporting goods or passengers. International voyages take place when the ports of departure and

arrival are in different national territories. Fuels delivered for consumption by ships during

domestic transportation, fishing or military uses are not included here, but are considered part of

final consumption of energy (see para. 5.94 for “Domestic Navigation”). For the purposes of

energy statistics, International Marine Bunkers are not included in exports; they are recorded

separately due to their importance, e.g. for the estimation of greenhouse gas emissions.

5.15. International Aviation Bunkers are quantities of fuels delivered to civil aircraft of any

nationality for consumption during international flights transporting goods or passengers.

International flights take place when the ports of departure and arrival are in different national

territories. Fuels delivered for consumption by aircraft undertaking domestic or military flights are

not included here, but are considered part of final consumption of energy (see para. 5.91 for

“Domestic Aviation”). For the purposes of energy statistics International Aviation Bunkers are not

included in exports; they are recorded separately due to their importance, e.g. for the estimation of

greenhouse gas emissions.

5.16. Stock changes. For the purposes of energy statistics, stocks are quantities of energy

products that are held on the national territory and can be used to: (a) maintain service under

conditions where supply and demand are variable in their timing or amount due to normal market

fluctuations, or (b) supplement supply in the case of a supply disruption.43

Stocks used to manage a

supply disruption may be called ”strategic” or “emergency” stocks and are often held separately

from stocks designed to meet normal market fluctuations, but both are considered here. Stock

changes are defined as the increase (stock build) or decrease (stock draw) in the quantity of stocks

over the reporting period and thus are calculated as a difference between the closing and opening

stocks.

5.17. Transfers are essentially statistical devices to overcome practical classification and

presentation issues resulting from changes in use or identity of a product. Transfers comprise

41 See International Merchandise Trade Statistics: Concepts and Definitions 2010, United Nations (2010).

42 These definitions differ from those used in the national accounts where exports and imports are defined as

transactions between residents and non-residents. Therefore, compilers of energy accounts should make necessary

adjustments to basic energy statistics before using them.

43 The notion of stocks dealt with in this chapter corresponds to what in economic statistics and national accounts is

referred to as “inventories”.

72

products transferred and interproduct transfers. Products transferred refers to the reclassification

(renaming) of products which, for example, is necessary when finished oil products are used as

feedstock in refineries. Interproduct transfers refer to the movements of fuels between product

categories because of reclassification of a product which no longer meets its original specification.

For example, aviation turbine fuel which has deteriorated or has been spoiled may be reclassified

as heating kerosene.

5.18. Transformation is the process where part or all of the energy content of a product entering

a process moves from this product to one or more different products leaving the process (e.g., from

coking coal to coke, from crude oil to oil products, or from fuel oil to electricity). (See section D.2

for further discussion.).

5.19. Losses refer to losses during the transmission, distribution and transport of fuels, heat and

electricity. Losses also include venting and flaring of manufactured gases, losses of geothermal

heat after production and pilferage of fuels or electricity. However, production of secondary gases

includes quantities subsequently vented or flared. This ensures that a balance can be constructed

between the use of the primary fuels from which the gases are derived and the production of the

gases.

5.20. Energy Industries Own Use refers to the consumption of fuels and energy for the direct

support of the production and preparation for use of fuels and energy, except heat not sold. As

such, it covers not only own use by energy industries as defined in para. 5.23, but also by other

energy producers as defined in para. 5.75. Quantities of fuels transformed into other fuels or energy

are not included here, but within transformation; neither are quantities used within parts of the

energy industry not directly involved in the activities listed in the definition. These quantities are

reported within final consumption.

5.21. Non-Energy Use consists of the use of energy products as raw materials for the

manufacture of products outside the scope of SIEC, as well as for direct uses that do not involve

using the products as a source of energy, nor as a transformation input. Examples are lubrication,

sealing, preservation, road surfacing and use as a solvent.44

5.22. Final Consumption refers to all fuel and energy delivered to users for both their energy

and non-energy uses, and which do not involve a transformation process as defined in para. 5.18.

44 Some studies of the non-energy use of fuels also classify the use of reductants as non-energy use; however, in energy

statistics the use of reductants (mostly for the manufacture of iron and steel) is considered as use for energy purposes,

because the gases created by the reduction process, which contain most of the carbon from the reductant, are used as

fuels to sustain the process or for other heat raising purposes. Reductants are carbon from fuels (usually cokes) that are

heated with metal oxides. During the process, the formation of carbon monoxide removes the oxygen from the metal

oxides and produces the pure metal.

73

D. Energy industries

5.23. Definition of energy industries. Energy production is an energy flow of major importance.

Data on energy production are required for various policy and analytical purposes; therefore, the

provision of further details on energy production is one of the priorities of energy statistics. Energy

can be produced by various economic units. However, not all of them should be treated as

belonging to energy industries. In order to ensure international comparability, it is recommended

that energy industries be defined as consisting of economic units whose principal activity45

is

primary energy production, transformation of energy or distribution46

of energy. For practical

reasons, a few additions are made, as described in para. 5.26.

5.24. Statistics on energy industries. To have a better understanding of the efforts of a country to

extract, produce, transform and distribute energy products, it is recommended that the collection,

compilation and dissemination of statistics describing the main characteristics and activities of

energy industries be considered as part of official energy statistics.

Box 5.1: Principal, secondary and ancillary activities

5.25. Energy industries are engaged in primary production, transformation and distribution of

energy products. These activities are very diverse and their detailed technical descriptions quite

complex. However, for the purposes of energy statistics, activities of economic units belonging to

energy industries can be conveniently identified by the establishments (plants) in which they occur.

For example, the typical representatives of primary production are coal mines and oil and gas

extraction plants.

45 For a more detailed definition of principal activity see Box 5.1.

46 Note that distribution here refers to distribution systems (consisting, for example, of lines, meters, wiring and pipes)

that convey energy products received from the generation facility or the transmission system to the final consumer, and

not the “transmission systems” that convey the energy products from the generation facility to the distribution system.

Distribution here also excludes the wholesale of energy products (for example, bottled gases).

The principal activity of a producer unit is the activity whose value added exceeds that of any other

activity carried out within the same unit. (2008 SNA para. 5.8)

A secondary activity is an activity carried out within a single producer unit in addition to the

principal activity and whose output, like that of the principal activity, must be suitable for delivery

outside the producer unit. The value added of a secondary activity must be less than that of the

principal activity, by definition of the latter. (2008 SNA para. 5.9)

An ancillary activity is incidental to the main activity of an enterprise. It facilitates the efficient

running of the enterprise but does not normally result in goods and services that can be marketed.

(2008 SNA para. 5.10).

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5.26. Activities of energy industries. In order to improve cross-country comparability of statistics

on energy production by energy industries it is recommended that countries identify, as far as

feasible and applicable, the energy industries listed in the left column of Table 5.1. It is important

to note that it considers a broader definition of energy industries than the core mentioned in para.

5.23, covering some plants, such as blast furnaces, for which the main activity is not energy-

related. Table 5.1 also provides information on the International Standard Industrial Classification

of All Economic Activities (ISIC), Rev. 4 categories (division/group/class) where the different

energy industries can be found.

Table 5.1: Energy industries with reference to the relevant ISIC category

Energy industry ISIC Rev. 4

Electricity, CHP and heat plantsa Division: 35 - Electricity, gas, steam and air conditioning supply

Pumped storage plants

Coal mines Division: 05 - Mining of coal and lignite

Coke ovens Group: 191 - Manufacture of coke oven products

Coal liquefaction plants Group: 192 - Manufacture of refined petroleum products

Patent fuel plants Group: 192 - Manufacture of refined petroleum products

Brown coal briquette plants Group: 192 - Manufacture of refined petroleum products

Gas worksb (and other conversion to

gases)

Group: 352 - Manufacture of gas; distribution of gaseous fuels

through mains

Gas separation plants Division: 06 – Extraction of crude petroleum and natural gas

Gas-to-liquids (GTL) plants Group: 192 – Manufacture of refined petroleum products

LNG plants / regasification plants Group: 091 - Support activities for petroleum and natural gas

extraction Class: 5221 - Service activities incidental to land transportation

Blast furnaces Group: 241 - Manufacture of basic iron and steel

Oil and gas extraction Division: 06 - Extraction of crude petroleum and natural gas

Group: 091 – Support activities for petroleum and natural gas extraction

Oil refineries Group: 192 - Manufacture of refined petroleum products

Charcoal plantsc Class: 2011 - Manufacture of basic chemicals

Biogas production plantsd Group: 352 - Manufacture of gas; distribution of gaseous fuels

through mains

Nuclear fuel extraction and fuel processing Class 0721 - Mining of uranium and thorium ores

Class: 2011 - Manufacture of basic chemicals

Other energy industry not elsewhere

specified e

Class: 0892 – Extraction of peat

…. a Also including the distribution of electricity and heat to consumers.

b Also including the distribution of these gases.

c The provided ISIC link refers to the production of charcoal through distillation of wood. If charcoal is produced in

the forest using traditional methods, the activity would be classified in ISIC 0220 (“Logging”).

d Plants having the production of biogases as their main activity would be classified in ISIC class 3520, as indicated

in the table above. However, biogases may also be produced as by-products of other activities, such as those

classified in ISIC 3700 (“Sewerage”) and 3821 (“Treatment and disposal of non-hazardous waste”).

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e The given ISIC link provides an example, namely the extraction of peat, but is not exhaustive.

5.27. A brief description of the energy industries of Table 5.1 is presented below.

5.28. Electricity, combined heat and power (CHP) and heat plants: See section 1 below for a

detailed presentation of these activities.

5.29. Coal mines are plants extracting coal through underground or open-cast mining. In addition

to the extraction activity itself, the operation of coal mines also includes operations such as

grading, cleaning, compressing, etc., leading to a marketable product.

5.30. Coke ovens are large ovens within which coke oven coke, coke oven gas and coal tars are

produced by high temperature carbonization of coking coal.

5.31. Coal liquefaction plants are plants where coal is used as a feedstock to produce liquid

fuels by hydrogenation or carbonization. They are also known as coal to liquid (CTL) plants.

5.32. Patent fuel plants are plants manufacturing patent fuel.

5.33. Brown coal briquette plants are plants manufacturing brown coal briquettes (BKB).

5.34. Gas works (and other conversion to gases) are plants manufacturing gases for

distribution to the public either directly or after blending with natural gas. Note that the gases are

collectively referred to as “Gas Works Gas and other manufactured gases for distribution”; short

name - gas works gas. Some gas works may produce coke, as well as gas.

5.35. Gas separation plants are plants involved in the separation of associated gas from crude

oil, and/or the separation of condensate, water, impurities and natural gas liquids from natural gas.

In addition to the above, the activities of these plants may also involve fractionation of the

recovered natural gas liquids.

5.36. Gas-to-liquids (GTL) plants are plants in which natural gas is used as a feedstock for the

production of liquid fuels. The liquid fuels are usually used as vehicle fuels. Note that the GTL

plants are quite different from liquefied natural gas (LNG) plants which convert gaseous natural

gas into liquid natural gas.

5.37. LNG plants/regasification plants are plants for carrying out liquefaction and/or

regasification of natural gas for the purpose of transport. This activity can be carried out on or off

the actual point of production.

5.38. Blast furnaces are furnaces which produce blast furnace gas as a by-product when making

pig iron from iron ore. During the process, carbon, mainly in the form of coke, is added to the blast

furnace to support and reduce the iron oxide charge and provide heat. Blast furnace gas comprises

carbon monoxide and other gases formed during the heating and reduction process.

5.39. Oil and gas extraction are activities of extracting crude oil, mining and extracting oil from

oil shale and oil sands, extracting natural gas and recovery of natural gas liquids. This includes

overall activities of operating and/or developing oil and gas field properties, including such

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activities as drilling, completing and equipping wells, operating separators, emulsion breakers,

desilting equipment and field gathering lines for crude petroleum and all other activities in the

preparation of oil and gas up to the point of shipment from the producing site.

5.40. Oil refineries are plants that transform crude oil and other hydrocarbons (together with

additives, feedstocks and natural gas liquids) into finished oil products. Typical finished products

are liquefied petroleum gases, naphtha, motor gasoline, gas oils, aviation fuels and other kerosene,

and fuel oils.

5.41. Charcoal plants are plants in which wood, or other vegetal matter is carbonized through

slow pyrolysis to produce charcoal.

5.42. Biogas production plants are plants for capturing and/or manufacturing biogases.

Biogases arise from the anaerobic fermentation of biomass. They can be derived from several

sources, including landfills, sewage sludge and agricultural residues. They also include synthesis

gas produced from biomass.

5.43. Nuclear fuel extraction and fuel processing refers to plants involved in the mining of ores

chiefly valued for their uranium and thorium content, the concentration of such ores, the

production of yellowcake, the enrichment of uranium and thorium ores, and/or the production of

fuel elements for nuclear reactors.

5.44. Other energy industry not elsewhere specified. This is a residual category which refers to

any energy industry not covered elsewhere in the list above. One example is the extraction of peat

for energy purposes.

1. Electricity and heat

5.45. Statistics on electricity and heat (SIEC Section 7 - Electricity and Section 8 - Heat) are

collected according to the type of producer and type of generating plant. Two types of producers

are distinguished:47

• Main Activity Producer. These are units that produce electricity or heat as their principal

activity. Formerly known as public utilities, these enterprises may be privately or publicly

owned companies.

• Autoproducers (electricity). These are units that produce electricity but for which the

production is not their principal activity.

Autoproducers (Heat). These are units that produce heat for sale but for which the

production is not their principal activity. Deliveries of fuels for heat generated by a unit for

its own purposes are classified as final consumption, and not as transformation inputs.

47 The definitions refer to “units”, which in practice will often be chosen as establishments but could also refer to

enterprises or households, depending on circumstances and data availability.

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5.46. It should be noted that any own use by the autoproducer in support of the production of

electricity and/or production of heat for sale should be reported under energy industries own use in

the same way that the inputs to and the output of electricity and heat sold figure under

transformation processes. Energy consumed in support of the principal economic activity should be

reported under final consumption (or again in energy industries own use if the autoproducer

happens to be an energy industry such as an oil refinery).

5.47. Three types of generating plants are also distinguished:

• Electricity plants refer to plants producing only electricity. The electricity may be

obtained directly from natural sources such as hydro, geothermal, wind, tidal, marine, solar

energy or from fuel cells, or from the heat obtained from the combustion of fuels or nuclear

reactions.

• CHP plants refer to plants which produce both heat and electricity from at least one

generating unit in the plant. They are sometimes referred to as “co-generation” plants.

• Heat plants refer to plants (including heat pumps and electric boilers) designed to produce

heat only for deliveries to third parties. (Deliveries of fuels for heat generated by an

autoproducer for its own purposes are classified as final consumption.)

5.48. The different data reporting requirements for the production and use of fuels are

summarised schematically in Table 5.2.

Table 5.2: Main activity producers and autoproducers of electricity and heat

Types of Plant:

Types of Producer:

Electricity plant CHP plant Heat plant

Main activity producers

Report all production

and all fuel used

Report all electricity and heat

produced and all fuel used

Report all heat

produced and all fuel

used

Autoproducer

Report all electricity produced

and heat sold with

corresponding fuel used

Report heat sold and

corresponding fuel used

Source: IEA Electricity Questionnaire reporting instruction

5.49. Note that pumped storage plants are plants where electricity is used during periods of lower

demand to pump water into reservoirs for subsequent release and electricity generation during

periods of higher demand. Less electricity is eventually produced than is consumed to pump the

water into the higher reservoir.

5.50. The different types of technology/processes for the generation of electricity and heat are

defined as follows.

5.51. Solar photovoltaics (PV) electricity refers to electricity produced from solar

photovoltaics, i.e. by the direct conversion of solar radiation through photovoltaic processes in

semiconductor devices (solar cells), including concentrating photovoltaic systems.

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5.52. Solar thermal electricity refers to electricity produced from solar heat (both concentrating

and non-concentrating, see para. 5.62).

5.53. Wind electricity refers to electricity produced from devices driven by wind.

5.54. Hydro electricity refers to electricity produced from devices driven by fresh, flowing or

falling water.

5.55. Wave electricity refers to electricity produced from devices driven by the motion of waves.

5.56. Tidal electricity refers to electricity generated from devices driven by tidal currents or the

differences of water level caused by tides.

5.57. Other marine electricity refers to electricity generated from devices which exploit sources

of marine energy not elsewhere specified. Examples of such sources are non-tidal currents,

temperature differences and salinity gradients in seas or salinity differences between sea and fresh

water.

5.58. Geothermal electricity refers to the electricity generated from the heat from geothermal

sources.

5.59. Nuclear electricity refers to electricity generated by nuclear heat.

5.60. Electricity from chemical processes refers to electricity generated from heat recovered

from a non-combusting chemical reaction.

5.61. Electricity from other sources refers to electricity produced from sources not elsewhere

specified (including fuel cells).

5.62. Solar Heat refers to the generation of heat from solar thermal (concentrating and non-

concentrating). Heat from concentrating solar thermal refers to high temperature heat produced

from solar radiation captured by concentrating solar thermal systems. The high temperature heat

can be transformed to generate electricity, drive chemical reactions, or be used directly in industrial

processes. Heat from non-concentrating solar thermal refers to low temperature heat produced

from solar radiation captured by non-concentrating solar thermal systems. The heat can be used for

applications, such as space heating, cooling, water heating, district heating and industrial

processes.

5.63. Geothermal heat refers to heat extracted from the earth. The sources of the heat are

radioactive decay in the crust and mantle and heat from the core of the earth. Heat from shallow

geothermal sources includes heat gained by the earth through direct sunlight and rain. The heat is

usually extracted from the earth in the form of heated water or steam.

5.64. Nuclear heat refers, for the purposes of energy statistics, to the heat obtained from a

working fluid (possibly steam) in the nuclear reactor. A working fluid is the substance circulated in

a closed system to convey heat from the source of heat to its point(s) of use.

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5.65. Heat and/or electricity from combustible fuels refers to the production of heat and/or

electricity from the combustion of fuels which are capable of igniting or burning, i.e. reacting with

oxygen to produce a significant rise in temperature.

5.66. Heat from chemical processes refers to recovered heat generated in the chemical industry

by exothermic reactions other than combustion, and used for steam-raising or other energy

purposes.

5.67. Heat from other sources refers to heat from sources not elsewhere specified.

2. Transformation processes

5.68. Transformation processes play a vital role in the flow of energy throughout an economy as

they ensure that primary energy products that cannot be directly or effectively utilized are changed

into other energy products more suitable for consumption. It is important to identify such processes

in order to describe more precisely and analyse energy transformation and assess the resources

necessary for carrying it out. In energy balances, energy transformation processes are reflected in

the rows of the transformation block (see Chapter 8 for more detail).

5.69. From the point of view of energy statistics, a transformation process is the movement of

part or all of the energy content of a product entering the process to one or more different products

leaving the process. There are two groups of transformation processes:

(a) The physical or chemical conversion of a product into another product or products

whose intrinsic properties differ from those of the original product. Examples are:

• chemical or physical changes to the input product(s) resulting in the creation of

products containing new chemical compounds (e.g., refining);

• physical changes to the input which involves separation into several different

products with intrinsic physical properties that are different from those of the input

material (e.g., coke oven carbonization of coal);

• conversion of heat into electricity; and

• production of heat from combustion or electricity.

(b) The aggregation or blending of products, sometimes involving a change of physical

shape. Examples are:

• blending of gases to meet safety and quality requirements before distribution to

consumers; and

• briquetting of peat and brown coal.

5.70. These transformation processes are currently identified by the plants in which they occur,

namely:

Electricity plants

Combined heat and power (CHP) plants

80

Heat plants

Coke ovens

Coal liquefaction plants

Patent fuel plants

Brown coal briquette plants

Gas works (and other conversion to gases)

Gas-to-liquids (GTL) plants

Blast furnaces

Oil refineries

Charcoal plants

Peat briquette plants

Natural gas blending plants

Petrochemical plants

Other transformation processes not elsewhere classified

5.71. Most of these plants have already been described in the context of table 5.1. Descriptions of

the remaining plants, which would appear under “Other energy industry not elsewhere specified”

in table 5.1, are given below:

5.72. Peat briquette plants are plants manufacturing peat briquettes.

5.73. Natural gas blending plants are plants, separate from gas works, in which substitute

natural gas (see gas works gas), petroleum gases or biogases are mixed with natural gas for

distribution in the gas mains. Where blending of substitute natural gas with natural gas takes place

within gas works the blending is considered part of the gas works process.

5.74. Petrochemical plants are plants which convert hydrocarbon feedstock into organic

chemicals, intermediate compounds and finished products, such as plastics, fibres, solvents and

surfactants. Feedstock used by the plant is usually obtained from a refinery and includes naphtha,

ethane, propane and middle distillate oils (for example, gas oil). The carbon and hydrogen in the

feedstock are largely transferred to the basic chemicals and products subsequently made from

them. However, certain byproducts are also created and returned to the refinery (such as pyrolysis

gasoline), or burned for fuel to provide the heat and electricity required for cracking and other

processes in the petrochemical plant. Note that since energy transformation is not the principal

activity of petrochemical plants they do not belong to energy industries and, as a group, are treated

as energy consumers (see table 5.3). However, the energy transformation performed by these plants

is reflected in the middle block of the energy balances (see Chapter 8).

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E. Other energy producers

5.75. Other energy producers are economic units (including households) which choose, or are

forced by circumstance, to produce energy for their own consumption and/or to supply energy to

other units, but for which energy production is not their principal activity. These units are engaged

in the production, transformation and transmission/distribution of energy as a secondary or

ancillary activity. This means that the “energy” output generated by these activities and measured

in terms of value added does not exceed that of the principal activity of the unit. In the case of

ancillary activities, the activities are carried out to support the principal and secondary activity of

the unit.

5.76. Geographically remote industries may have no access to electricity unless they produce it

themselves; iron and steel works requiring coke and the heat from it for their own production

purposes will often produce their own coke and electricity. Sugar mills nearly always burn the

bagasse they produce for generating steam, and process heat and electricity. An enterprise whose

primary activity is the production of animal products (i.e., raising and breeding of pigs, sheep, etc.)

could use its animal waste as fuel in a biogas system to generate electricity for its own use or to sell

to a local market. Many industrial establishments and commercial organizations may have

electricity generating equipment that they can turn on in the event of failure in the public supply

system (in which case they might even sell electricity to other consumers or to the public supply

system). Households that use solar panels for generating electricity for their own use (and

sometimes even for sale to third parties) are another example of other energy producers.

5.77. It is recognized that the collection of data on energy production by other energy producers

might be challenging. However, it is recommended that countries, where such producers account

for a significant part of total energy production, make efforts to obtain from them the detailed data

and incorporate them in their official energy statistics, including in energy balances. The energy

used in these processes should be recorded under transformation and energy industries own use

(see para. 5.86 and 5.87).48

Countries where the production of energy by non-energy industries is

small (as determined by the agency responsible for compilation and dissemination of official

energy statistics) might limit their data collection from such industries to appropriate aggregates

only or prepare estimates as necessary.

F. Energy consumers and energy uses

5.78. Similar to information on energy producers, information on energy consumers is important

for both energy policy and analytical purposes, as it allows for the formulation and monitoring of

policies targeted, for example, to reinforcing and/or modifying consumption patterns. This section

48 This is similar to treating these secondary and ancillary activities related to energy as performed by a separate unit

for collection purposes, while maintaining the definition of autoproducers in para. 5.45.

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defines the major groups of energy consumers used in energy statistics and describes a cross

classification between groups of users and types of uses.

1. Energy consumers

5.79. In energy statistics, energy consumers consist of economic units (enterprises and

households) that act as final users of energy; they use energy products for energy purposes (heat

raising, transportation and electrical services) and/or for non-energy purposes. It should be noted

that the economic units belonging to the energy industries that use energy to produce other energy

products - are excluded from this group. Their energy use, by convention, is not part of the final

consumption of energy and is considered separately as energy industries own use (see para. 5.20).

5.80. It is recommended that countries identify, as far as feasible and applicable, the groups of

energy consumers as listed in Table 5.3. To facilitate the collection of energy statistics and their

integration with other economic statistics, Table 5.3 also provides a correspondence between the

identified groups of energy consumers and the relevant categories of ISIC Rev. 4.

5.81. The scope of each consumer group is defined by the scope of the economic units belonging

to ISIC Rev.4 categories in Table 5.3, except for “households”, which includes all households in

their capacity as final consumers and not only those engaged in economic activities (as covered by

ISIC).49

Table 5.3: Main categories of energy consumers

Energy consumers Correspondence to ISIC Rev. 4

Manufacturing, construction and non-fuel

mining industries

Iron and steel ISIC Group 241 and Class 2431

Note that the consumption of energy products in coke ovens and

blast furnaces is excluded, as these plants are considered part of the energy industries.

Chemical and petrochemical ISIC Divisions 20 and 21

Note that the consumption of energy products by plants

manufacturing charcoal or carrying out the

enrichment/production of nuclear fuels (both classified in ISIC

2011) is excluded, as these plants are considered part of the

energy industries.

Non-ferrous metals ISIC Group 242 and Class 2432

Non-metallic minerals ISIC Division 23

Transport equipment ISIC Divisions 29 and 30

Machinery ISIC Divisions 25, 26, 27 and 28

49 ISIC Divisions 97 and 98 only cover households engaged in economic activities (as employers or as producers of

undifferentiated goods or services for own use).

83

Mining and quarrying ISIC Divisions 07 and 08 and Group 099, excluding the mining

of uranium and thorium ores (Class 0721) and the extraction of

peat (Class 0892).

Food and tobacco ISIC Divisions 10, 11 and 12

Paper, pulp and print ISIC Divisions 17 and 18

Wood and wood products (Other than pulp

and paper)

ISIC Division 16

Textile and leather ISIC Divisions 13, 14 and 15

Construction ISIC Divisions 41, 42 and 43

Industries not elsewhere specified ISIC Divisions 22, 31 and 32

Household ISIC Divisions 97 and 98

Commerce and public services ISIC Divisions 33, 36-39, 45-96 and 99, excluding ISIC 8422

Agriculture, Forestry ISIC Divisions 01 and 02

Fishing ISIC Division 03

Not elsewhere specified (including Defence activities)

ISIC Class 8422

5.82. It should be noted that the consumption of energy by defence activities (ISIC 8422) is

recorded in the balance as "not elsewhere specified" as it includes all defence consumption of

energy products, including for transport, bunkering, etc. (See also Chapter 8 on energy balances.)

2. Cross classification of uses and users of energy

5.83. Energy products can be used for three purposes: (i) energy purposes; (ii) non-energy

purposes; and (iii) transformation. The use of energy products for energy purposes is further

broken down into two categories: for any energy purposes excluding transportation; and

transportation purposes. In basic energy statistics and energy balances, data on the use of energy

are presented by cross-classifying them by purpose and user groups (various categories of energy

industries and energy consumers) as presented in Table 5.1 and Table 5.3, respectively.

5.84. An illustration of this cross classification is presented in matrix form in Figure 5.2, which

shows the various uses of energy by purpose (by column) and the different users, i.e. energy

industries and energy consumers (by row). Each cell, defined by the intersection of columns and

rows, represents the use of energy products for specific purposes by a specific user.

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Figure 5.2: Cross classification of uses and users of energy

5.85. The matrix presented in the above figure can be used to illustrate earlier defined important

concepts.

5.86. Transformation is represented in Figure 5.2 by Box (a), which goes across all economic

units within the territory of reference to take into account not only the transformation that occurs in

energy industries but also the transformation that might occur as a secondary and/or ancillary

activity by energy consumers. Statistics on transformation are disaggregated and presented

according to the list in para. 5.70. When the transformation takes place outside the energy

industries (i.e., by other energy producers) the energy consumed in the transformation is recorded

under the most relevant category of the disaggregation, i.e. the most similar energy industry.

5.87. Energy industries own use is represented by Box (b). As explained earlier in the text, it

does not cover the use of energy products for transport or non-energy purposes by the energy

industries. On the other hand, it also covers own use in energy production by other energy

producers, i.e. economic units that produce energy products but are not part of the energy

industries based on their principal activity.

5.88. Final energy consumption refers to all fuel and energy delivered to users for their energy

use. This is represented in Figure 5.2 as follows:

(i) The use of energy products for energy purposes (excluding for transportation) by energy

consumers – Box (c); and

(ii) The use of energy for transport by all economic units – Box (d).

85

Transport

5.89. Use of energy products for transportation purposes, Box (d), is defined as the consumption

of fuels and electricity used to transport goods or persons between points of departure and

destination within the national territory irrespective of the economic sector within which the

activity occurs. The classification of the consumption of fuels by merchant ships and civil aircraft

undertaking the transport of goods or persons to another national territory is covered under the

definitions for International Marine and Aviation Bunkers and is therefore excluded from this

definition. However, deliveries of fuels to road vehicles going beyond national borders cannot be

readily identified and by default are included here.

5.90. Transport can be disaggregated by mode of transport as indicated in Table 5.4 below:

Table 5.4: Mode of transport

Transport

Road

Rail

Domestic aviation

Domestic navigation

Pipeline transport

Transport not elsewhere specified

5.91. Domestic aviation refers to quantities of aviation fuels delivered to all civil aircraft

undertaking a domestic flight transporting passengers or goods, or for purposes such as crop

spraying and the bench testing of aero engines. A domestic flight takes place when the departure

and landing airports are on national territory. In cases where distant islands form part of the

national territory, requiring long flights through the air space of other countries, those flights are,

nevertheless, considered part of domestic aviation. Military use of aviation fuels should not be

included in domestic aviation but under the energy balance item “not elsewhere specified”. The use

of fuel by airport authorities for ground transport within airports is also excluded here, but included

under “Commerce and Public Services”.

5.92. Road refers to fuels and electricity delivered to vehicles using public roads. Fuels delivered

for “off-road” use and stationary engines should be excluded. Off-road use comprises vehicles and

mobile equipment used primarily on commercial industrial sites or private land, or in agriculture or

forestry. The deliveries of fuels related to these uses are included under the appropriate final

consumption heading. Deliveries for military uses are also excluded here but included under “not

elsewhere specified”. The fuel use for freight transport by road and by trolley buses is included

here.

5.93. Rail refers to fuels and electricity delivered for use in rail vehicles, including industrial

railways. This includes urban rail transport (including trams).

5.94. Domestic navigation refers to fuels delivered to vessels transporting goods or people and

undertaking a domestic voyage. A domestic voyage is between ports of departure and destination

86

in the same national territory without intermediate ports of call in foreign ports. Note that this may

include journeys of considerable length between two ports in a country (e.g., San Francisco to

Honolulu). Fuels delivered to fishing vessels are excluded here but included under “fishing”.

5.95. Pipeline transport refers to fuels and electricity used in the support and operation of

pipelines transporting gases, liquids, slurries and other commodities between points within the

national territory. It comprises the consumption at pumping stations and for the maintenance of the

pipeline. Consumption for maintaining the flow in pipelines carrying natural gas, manufactured

gas, hot water and steam in distribution networks is excluded here, but included under the

appropriate heading within “Energy Industries Own Use”. Consumption for the transport of natural

gas in transmission networks is included. Consumption of fuels or electricity for maintaining the

flow in pipelines carrying water is included in ‘commerce and public services’. A transmission

pipeline transports its contents to distribution pipelines for eventual delivery to consumers.

Transmission pipelines for gas usually operate at pressures considerably higher than those used in

distribution pipelines.

5.96. Transport not elsewhere specified refers to deliveries of fuels or electricity used for

transport activities not covered within the modes of transport defined elsewhere. Most of the forms

of transport listed in ISIC Class 4922 (other land transport) are included in the modes of transport

defined elsewhere. However, consumption of electricity for téléphériques (telfers), and ski and

cable lifts would be included here.

5.97. Non energy use of energy products is represented in Figure 5.2 by Box (e) and covers the

use of energy products for non-energy purposes, irrespective of the economic activity where the

use takes place (energy consumers or energy industries). This use is usually presented in an

aggregated form and thus not linked to any specific economic activity (see also Chapter 8).

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Chapter 6. Statistical Units and Data Items

A. Introduction

6.1. The aim of this chapter is to describe entities about which information is sought and for

which energy statistics are ultimately compiled (i.e. statistical units), and to provide a reference list

of data items to be collected from those entities in order to assist countries in the organization of

their data collection activities and ensure maximum possible comparability of the collected data

with other economic statistics. The clear identification of the statistical units and their consistent

use is a fundamental precondition for obtaining unduplicated and comparable data about any

phenomenon under investigation, including energy.

6.2. It should be noted that the definitions of most of the data items are determined by the

definitions of the relevant energy products (see Chapter 3) and flows (see Chapter 5), and are not

reproduced in this chapter. However, if certain data items are not covered in Chapters 3 and 5, or

need further elaboration, additional explanations are provided.

6.3. The list of data items presented in this chapter represents a reference list in the sense that it

contains all generally desirable data items for the compilation and dissemination of energy

statistics as part of official statistics. It is recommended that countries use the reference list of

data items for selecting data items for use in their national energy statistics programmes, in

accordance with their own circumstances, respondent load and available resources. It is further

recommended that the data items be selected in a way to allow for an adequate assessment of the

country’s energy situation, reflect main energy flows specific to the country and enable, as a

minimum, the compilation of energy balances in an aggregated format. It is recognized that the

compilation of energy statistics is a complex process and involves both direct data collection by

energy statisticians, as well as the re-use of data collected via other national statistics, such as

enterprise, foreign trade and price statistics, household statistics, and data from administrative

sources. The agency responsible for the overall official energy statistics programme should be

aware of the advantages and shortcomings of these other statistics and make efforts to assemble the

various data into a coherent data set that best match the expectations of users.

B. Statistical units

1. Statistical units and their definitions

6.4. A statistical unit is an entity about which information is sought and for which statistics are

ultimately compiled. It is also the unit at the basis of statistical aggregates and to which tabulated

data refer. Because of the diversity of economic entities involved in the production, distribution

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and consumption of energy, energy data compilers should be aware of the different types of

statistical units in order to organize data collection, as well as to ensure that data are interpreted

and used correctly in conjunction with other statistics. The universe of economic entities involved

in the production, transformation and consumption of energy is vast. It varies from small local

energy producers or distributors to large and complex corporations engaged in many different

activities carried out at or from many geographical locations. These entities vary in their legal,

accounting, organizational and operating structures, and have different abilities to report data. The

concepts of statistical units and their characteristics briefly introduced below are intended to assist

energy statistics compilers to better organize their work.50

6.5. Statistical units can be divided into two categories: (a) Observation units – identifiable

legal/organizational or physical units which are able, actually or potentially, to report data about

their activities; and (b) Analytical units – units created by statisticians, often by splitting or

combining observation units in order to compile more detailed and homogeneous statistics than is

possible by using data on observation units. Although, analytical units are not able to report data

themselves about their activities, indirect methods of statistical estimation and imputation of such

data exist. The use of analytical units varies from country to country. It should be noted, however,

that the accuracy of energy statistics may be increased through the use of analytical units in cases

where complex economic entities are active in both energy production and other economic

activities. In this connection, countries are encouraged to use analytical units as necessary and

feasible in order to improve the quality of their energy statistics. Data about activities of statistical

units can be collected from those units themselves (i.e., through census or surveys) or from others

(i.e., administrative sources). (See Chapter 7 on data collection and compilation for details.)

6.6. For practical purposes of collecting energy statistics, the following statistical units are

differentiated and defined below: enterprise, establishment, kind-of-activity unit, unit of

homogeneous production and household.

6.7. Enterprise. An economic entity in its capacity as a producer of goods and services is

considered to be an enterprise if it is capable, in its own right, of owning assets, incurring liabilities

and engaging in economic activities and transactions with other economic entities. It is also an

economic transactor with autonomy in respect of financial and investment decision-making, and

with the authority and responsibility for allocating resources for the production of goods and

services. It may be engaged in one or more productive activities at one or more locations.

6.8. Establishment. An establishment is defined as an enterprise or part of an enterprise that is

situated in a single location and in which only a single productive activity is carried out, or in

which the principal productive activity accounts for most of the value added.51

Although the

50 For a detailed description of statistical units and their characteristics, see the DESA/UNSD paper "Statistical Units"

(ESA/STAT/2008/6), available at http://unstats.un.org/unsd/industry/docs/stat_2008_6.pdf.

51In energy statistics, the term “plant” is often used as an equivalent of the term “establishment”.

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definition of an establishment allows for one or more secondary activities to be carried out, their

magnitude should be small compared with that of the principal activity. If a secondary activity is as

important, or nearly as important, as the principal activity, then the unit is more like a local unit,

that is, an enterprise (or part of an enterprise) which engages in productive activities at or from one

location.

6.9. In the case of most small- and medium-sized businesses, the enterprise and the

establishment will be identical. In general, it is recommended that large enterprises engaged in

many economic activities that belong to different industries be broken up into one or more

establishments, provided that smaller and more homogeneous units can be identified for which data

on energy production or other activities attributed to energy industries may be meaningfully

compiled.

6.10. Kind-of-activity unit (KAU). Any given enterprise may perform many different activities,

both related and not related to energy. To focus on the part of the enterprise that is of interest to

energy statistics, an analytical statistical unit, called the kind-of-activity unit (KAU), may be

constructed and used by the energy data compiler. A KAU is defined as an enterprise or part of an

enterprise that engages in only one kind of productive activity or in which the principal productive

activity accounts for most of the value added. There is no restriction placed on the geographical

area in which the activity is carried out. Therefore, if there is only one location from which an

enterprise carries out that activity, the KAU and the establishment are the same units.

6.11. Unit of homogeneous production. To ensure the most complete coverage, energy statistics

compilers may need, in certain cases, to use an even more detailed splitting of the enterprise

activities. The statistical unit appropriate for such a purpose is the unit of homogeneous production.

It is defined as a production unit in which only a single (non-ancillary) productive activity is

carried out. For example, if an enterprise is engaged primarily in non-energy related activities, but

still produces some energy, the compiler may “construct” an energy producing unit which might be

classified under the proper energy activity category and collect (or estimate) data about its energy

production and inputs used in such a production (while maintaining the autoproducer definition of

para. 5.45 if the unit is an electricity or heat producer). This is the case, for example, of the sugar

industry, which burns bagasse to generate electricity for own use. While it may not be possible to

collect data corresponding to such a unit directly from the enterprise or establishment, in practice,

such data are calculated/estimated by transforming the data supplied by establishments or

enterprises on the basis of various assumptions or hypotheses.

6.12. Households. The scope of energy statistics also includes statistics (mainly on consumption)

in the household sector. In data collection from this sector, a special statistical unit – household – is

used. A household is defined as a group of persons who share the same living accommodation, who

pool some or all of their income and wealth, and who consume certain types of goods and services

collectively, mainly housing and food. In general, each member of a household should have some

claim upon the collective resources of the household. At least some decisions affecting

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consumption or other economic activities must be taken for the household as a whole.52

In some

cases, a household may also produce energy products for sale or for own use.

2. An illustrative example

6.13. In order to illustrate the different types of statistical units, an imaginary, but realistic

example is presented below. Figure 6.1 shows a schematic representation of a large corporation

involved in the primary production, transformation and distribution of energy. The corporation

consists of four separate companies (identified in the figure as company A, B, C and D) which

carry out activities of extraction, transportation, refining and sale of oil products. Each tile in the

figure represents a different geographical location. In each tile a description of the kind of

economic activity(ies) carried out at that location is described. For easy reference, the tiles are

numbered (1) to (8).

Figure 6.1: Example of a large oil corporation

52 2008 SNA, para. 4.149.

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6.14. Company A is engaged in the activity of crude oil extraction (ISIC Rev.4, Group 061). It

has plants at two different locations illustrated in the figure by tiles (1) and (2). The crude oil is

then transported through pipelines by company B (ISIC Rev.4, Group 493). Although the pipelines

themselves are geographically distributed, the centre of operation can be assigned to a physical

location and is illustrated by tile (3). Company B transports the crude oil to Company C, which

operates three separate refineries located in different geographical areas, illustrated by tiles (4), (5)

and (6). The refinery associated with tile (6) also has a minor secondary activity of electricity

generation (ISIC Rev.4, Group 351), from which small quantities of electricity are sold to third

parties.

6.15. Company C provides some of its refined oil products (i.e., motor gasoline, diesel, etc.) to

Company D, whose principal activity is the retail sale of motor gasoline and diesel (ISIC Rev.4,

Group 473) at the gasoline stations illustrated by tiles (7) and (8) in the figure. The gasoline station

at tile (8) also carries out retail sale of food, beverages, tobacco and miscellaneous household

equipment as a significant secondary activity (ISIC Rev.4 Group 471).

6.16. It should be noted that simply looking at the location and type of activity is not sufficient to

determine which of these units can be considered an enterprise, since an enterprise has to fulfil

additional criteria (see para. 6.7), including the capability of incurring liabilities and autonomy in

respect of financial transactions. For the purpose of this example, companies A, B, C and D are

assumed to individually fulfil these criteria and constitute four separate enterprises, while the units

represented by tiles do not (except for tile (3)).

6.17. Each of the installations in tiles (1) to (7) can then be considered to be an establishment,

since they are all situated in a single location and do not carry out secondary activities of any

significant magnitude. The gas station illustrated by tile (8) has a significant secondary activity of

other retail. If the magnitude of this activity is as important, or nearly as important as that of its

primary activity, this gas station could, for statistical purposes, be split into two separate

establishments.

6.18. Since the definition of a KAU does not depend on physical location, but considers only

productive activity, the installations at tiles (1) and (2) can collectively be considered one KAU.

Installation (3) can be considered a separate KAU. The same can be said for the installations at

tiles (4), (5) and (6) taken together. Whether or not the installations in (7) and (8) can be

considered together as a single KAU depends on the significance of the secondary activity in (8). If

this activity is important, it will have to be separated as a second KAU located in (8), similar to the

theoretical split mentioned in para. 6.17.

6.19. If the unit of homogeneous production (UHP) is considered for describing the example, the

installations at tiles (1) and (2) could be collectively considered a UHP, but not the installations at

tiles (4), (5) and (6), since the installation at (6) is also engaged in some electricity production. In

order to define units of homogeneous production, the installation at this tile needs to be

conceptually split into two parts: one for the refinery operation and another for the generation of

electricity. The installations at (4) and (5), together with the refinery part of the installation at (6)

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can collectively be considered a unit of homogeneous production, and the electricity generating

component of (6) can be considered as a separate unit (of homogeneous production). A similar

treatment has to be applied to tiles (7) and (8).

6.20. While the last two paragraphs illustrate a general approach, this is not recommended in the

case of energy statistics (see para. 6.21). The use of the UHP can be justified in certain cases (see

para. 6.11) but is usually not applied to the whole range of units covered by the statistics collected.

The use of enterprise, establishment, KAU or UHP may lead to different results (e.g. when broken

down by economic activity) and deviations from the recommendation in para. 6.21 should be

carefully weighed.

3. Statistical units for energy statistics

6.21. For the inquiries dealt with in the present recommendations, the statistical units should

ideally be the establishment and households. The establishment is recommended because it is the

most detailed unit for which the range of data required is normally available. For many analytical

applications, data need to be grouped according to such characteristics as kind-of-activity,

geographical area and size, and this is facilitated by the use of the establishment unit.

6.22. However, the choice of statistical unit will also be guided by the purpose of the data

collection, user needs and the availability of data. Therefore, the enterprise could also be used as

the statistical unit. In practice, in the majority of the cases, especially for smaller units, the

establishment and the enterprise are the same units.

C. Reference list of data items

6.23. This section provides the reference list of data items for use in national energy statistics,

aiming to satisfy basic needs of energy policy makers, the business community and the general

public, and to ensure the international comparability of such statistics. The list consists of five

parts: (i) data items on the characteristics of statistical units; (ii) data items on energy stocks and

flows; (iii) data items on production and storage capacity; (iv) data items for assessment of the

economic performance of the energy industries; and (v) data items on mineral and energy

resources.

1. Characteristics of statistical units

6.24. Data items on characteristics of statistical units are used for the unique identification of

units, their classification within particular activity groups and for the description of various aspects

of their structure, operation and relationship with other units. Information about these

characteristics of the statistical units allows for the compilation of statistics on the size of energy

industries as a whole, as well as on their economic and geographical structure. Also, it is a

precondition for an effective organization of statistical sample surveys, as well as for making

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comparisons and establishing linkages between energy data from different sources, thus

significantly reducing the duplication in data collection and the response burden.

6.25. The main characteristics of the statistical unit are: its identification code, location, kind of

activity, period of operation, type of economic organization, type of legal organization and

ownership, and size.

Item Number

Reference List Items

0.1 Identification code

0.2 Location

0.3 Kind-of-activity

0.4 Period of operation

0.5 Type of economic organization

0.6 Type of legal organization and ownership

0.7 Size

6.26. Identification code. The identification code is a unique number assigned to a statistical

unit.53

The unique identification of statistical units is necessary in order to: (i) allow their

registration in statistical business registers; (ii) permit the collection of information about them via

administrative sources; (iii) provide a sampling base for statistical surveys; and (iv) permit

demographic analysis of the population of units. The identification code must not change

throughout the life of the unit, although some of the units’ other characteristics may change.

Common identification codes shared with administrative authorities and other government

departments greatly facilitate the statistical work, including the connection of the statistical

business register, if such is established, with other registers.

6.27. Location. The location is defined as the place at which the unit is physically performing its

activities, not the location of its mailing address. This characteristic serves two important purposes.

First, to identify the units and classify them by geographical regions at the most detailed level as

demanded by the statistical programme, and second, if a unit operates in more than one location, to

allocate its economic activity to the location where it actually takes place. The latter is important

for sub-national analyses. Since the classification of units by location is of particular national

interest, any geographical classification should aim to distinguish sub-national levels (i.e.,

economic regions or administrative divisions, states or provinces, local areas or towns).

6.28. The details about mailing address, telephone and fax numbers, e-mail address and contact

person are also important identification variables since these details are used for mailing the

statistical questionnaires, written communication with the unit or making ad hoc queries about its

53 Such a code may comprise digits identifying its geographical location, kind-of-activity, whether a unit is a principal

producing unit or an ancillary unit, and link to its subsidiaries/principal if any, etc., although such practice is not

always recommended.

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activity. Up-to-date information about any changes in those variables is crucial for the efficient

work of statistical authorities.

6.29. Where an enterprise has more than one establishment, it may or may not have one location

and address. Often, the enterprise address is used for administrative purposes and the establishment

addresses for statistical purposes. There is, however, a need for care when dealing with large

complex enterprises. A multi-establishment enterprise should be requested to provide location

details about each of its establishments, or the establishment may be asked to provide the name and

location of the enterprise that owns it so that a data set in the register on the enterprise and its

component establishments can be established. In some cases, it may be necessary to correspond

with both the establishment and the enterprise if, for instance, the unit supplying employment

details is different from the one providing financial details.

6.30. Kind-of-activity. The kind-of-activity is the type of production in which a unit is engaged

and should be determined in terms of the national activity classification which, in turn, is

recommended to be based on the latest version of the International Standard Industrial

Classification of All Economic Activities (ISIC), Rev. 4 or be correlated with it.

6.31. Period of operation. This indicates the period the establishment has been in operation

during the reference period. It would be useful to seek information for the following items: (a) in

operation since (date) - important, for instance, for the determination of electricity installed

capacity as of a determined date; (b) temporary or seasonal inactivity - useful, for example, to track

refinery shut-downs which might explain a decrease in annual refinery throughput/output; (c)

ceased operation (date) - also important for determining installed capacity; and (d) sold or leased to

another operator (name of new operator), which might explain changes in electricity

capacity/production between main and autoproducers. Besides the information that this

characteristic provides about the activity status of the unit (active or temporarily inactive), it also

helps in interpreting the returns made by statistical units affected by seasonal factors and those

made by statistical units that began or ceased operations during the reference period. Most of such

information lies on the level of metadata and is useful for data quality checks.

6.32. Type of economic organization. The enterprise and the establishment are the main units

used by countries for conducting industrial surveys. The characteristic “type of economic

organization” is intended to indicate whether the establishment is the sole establishment of the

enterprise of immediate ownership or part of a multi-establishment enterprise. If further details are

required on this aspect of the industrial structure, the multi-establishment enterprises might be

divided into classes according to the number of their constituent establishments or by the criteria

used for classifying establishments (employment, value added) that are most appropriate for each

country.

6.33. For the purpose of accurate measurement of energy production and other energy flows and

for the compilation of various energy indicators, it is desirable to have the links between individual

establishments and their parent enterprise clearly defined. More importantly, these links are

fundamental for efficient sampling design and merging data obtained from different surveys

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covering both energy data and other variables needed to obtain indicators of energy industries’

performance.

6.34. Type of legal organization and type of ownership. The kind of legal organization is another

important characteristic and possible criterion for the stratification of economic entities in

statistical surveys. The type of legal organization is the legal form of the economic entity that owns

the unit. The minimum classification of units by type of legal organization distinguishes between

two main types, namely, incorporated units and unincorporated units. Incorporated units are legal

entities separate from their owners and include corporations, as well as other incorporated entities

such as cooperatives, limited liability partnerships and non-profit institutions. Unincorporated units

are not incorporated as legal entities separately from their owners and may include public agencies

that are part of the general government and sole proprietorships and partnerships owned by

households.

6.35. In addition to the kind of legal organization, the main types of ownership, namely, private

ownership and the various forms of public ownership of units, are useful optional characteristics.

The criterion for distinguishing between privately and publicly owned units should be based on

whether the ownership of the enterprise to which the establishment belongs rests with public

authorities or private parties. Public units are those units owned or controlled by government units,

whereas privately owned units are those owned or controlled by private parties. Public authorities

or private parties are considered to be the owners of a given enterprise if they own all, or a majority

of the unit’s shares, or its other forms of capital participation. Control over a unit consists of the

ability to determine the unit’s policy by choosing appropriate directors, if necessary.

6.36. The category of publicly owned units can undergo further disaggregation into the main

divisions of public ownership existing in each country, which would normally differentiate among

central government ownership, ownership by state or provincial governments and ownership by

local authorities. Within the group of privately owned units, a further classification of ownership,

which differentiates between nationally owned units and those under foreign control, could be

applied.54

6.37. Size. The size of a unit is an important data item for use in sample frame stratification and

grossing up techniques. In general, the size classes of statistical units can be defined in terms of

employment, turnover or other variables. In energy statistics, it might be necessary to define two

size measures depending on the main objective of the analysis (e.g., in order to study the

production/generation of energy it may be more appropriate to define the size of an establishment

in terms of the maximum capacity to generate energy products). This, however, may not be

applicable to all energy products. To study the consumption of energy products, it may be more

appropriate to measure the size of a unit by employment (for establishments) and number of

persons (for households).

54Further details on the type of legal organization and type of ownership are found in United Nations (2009b).

96

2. Data items on energy flows and stock levels

6.38. Data items presented in this section relate to the collection of statistics in physical units on

energy flows, such as production, transformation and consumption, as well as on stock levels of

different energy products. Such data items are designed to produce consistent time series that show

changes in the supply and demand for various energy products. They also provide the basis for

making comparisons and analysing the interrelationships between various energy products, and,

when the data items are expressed in common units, make possible the regular monitoring of

national energy patterns and the preparation of energy balances.

6.39. The data items in this section are presented in two sub-categories, namely: (i) data items

common for all energy products, and (ii) data items applicable to a specific energy product. These

data items are both required for the collection and dissemination of statistics on stocks and flows.

Recommendations on units of measurement are provided in Chapter 4.

Data items common for all energy products

6.40. For each product identified in SIEC, the following data items can be compiled as applicable

(See Chapter 5 for the definitions of the relevant energy flows and related concepts.).

Item

number Data item

1.1 Production

1.2 Total Imports

1.2.1 Imports by origina

1.3 Total Exports

1.3.1 Exports by destinationa

1.4 International Marine Bunkers

1.5 International Aviation Bunkers

1.6 Stocks at the end of the period

1.7 Stock Changes

1.8 Transfers

1.9 Transformation (by transformation processes)b

1.10 Losses

1.11 Energy usec

1.11.1 Of which: for transport (by type of transport)d

1.12 Non-Energy Use a It is acknowledged that acquiring precise information on origin of imports and destination of exports is not always

easy.

b The transformation processes are described in Chapter 5.

c Depending on the statistical unit, energy use (excluding transport) corresponds to energy industries own use if the

statistical unit is an energy industry (Table 5.1) - or final energy consumption if the unit is an energy consumer (Table

5.3).

97

d The breakdown of transport is provided in Table 5.4.

Data items applicable to a specific group of energy products

Coal and Peat

6.41. For products classified in SIEC under Section 0 (Coal) and Section 1 (Peat), the following

list of additional data items applies.

Item

number Data item

2.1 Production

2.1.1 Of which: Underground

2.1.2 Of which: Surface

2.2 Production from other sources

6.42. Underground production refers to production from underground mines where coal is

produced by tunnelling into the earth to the coal bed, and then mined with underground mining

equipment such as cutting machines and continuous, longwall or shortwall mining machines.

6.43. Surface production refers to production from surface mines, that is from coal-producing

mines where earth above or around the coal (overburden) is removed to expose the coal bed, which

is then mined with surface excavation equipment such as draglines, power shovels, bulldozers,

loaders and augers. These mines may also be known as area, contour, open-pit, strip or auger

mines.

6.44. Production from other sources consists of two components: (a) recovered slurries,

middlings and other low-grade coal products, which cannot be classified according to type of coal

and include coal recovered from waste piles and other waste receptacles; and (b) fuels whose

production is covered in other sections of SIEC, for example, from oil products (e.g. petroleum

coke addition to coking coal for coke ovens), natural gas (e.g., natural gas addition to gas works

gas for direct final consumption), biofuel and waste (e.g., industrial waste as binding agent in the

manufacturing of patent fuel).

Natural Gas

6.45. For products classified in SIEC under Section 3 – Natural Gas, the following list of

additional data items applies.

Item

number Data item

3.1 Production

3.1.1 Of which: Associated gas

3.1.2 Of which: Non-associated gas

3.1.3 Of which: Colliery and Coal Seam Gas

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3.2 Production from other sources

3.3 Extraction lossesa

3.3.1 Of which: gas flared

3.3.2 Of which: gas vented

3.3.3 Of which: gas re-injected

3.4 Gas flared (except during extraction)

3.5 Gas vented (except during extraction) a These are losses that occur during the extraction of natural gas and are not included under the production of natural

gas. See para. 5.10 for the definition of production.

6.46. The production of natural gas refers to the dry marketable production within national

boundaries, including offshore production. Production is measured after purification and extraction

of natural gas liquids (NGLs) and sulphur. Extraction losses and quantities reinjected, vented or

flared are not included in the figures for primary production (see para. 5.10). Production includes

quantities used within the natural gas industry; in gas extraction, pipeline systems and processing

plants. Production is disaggregated for the following:

Associated gas: natural gas produced in association with crude oil;

Non-associated gas: natural gas originating from fields producing hydrocarbons only in

gaseous form;

Colliery and coal seam gas: methane produced at coal mines or from coal seams, piped to

the surface and consumed at collieries or transmitted by pipeline to consumers.

6.47. Production from other sources refers to the production of gas from energy products that

have been already accounted for in the production of other energy products. Examples are the

blending of petroleum gases, manufactured gases or biogases with natural gas.

6.48. Extraction losses refer to the losses that take place during extraction and are not included in

the production of natural gas. In particular, they refer to:

Gas flared: Natural gas disposed of by burning in flares, usually at production sites or at

gas processing plants.

Gas vented: Natural gas released into the air at the production site or at processing plants.

Gas reinjected: The reinjection of natural gas into an oil reservoir in an attempt to increase

oil recovery.

6.49. Flaring and venting, however, can also take place after the production of natural gas, for

example, in the manufacture and transformation of certain gases. In this case, the gas flared and

vented should also be separately reported. These quantities would be implicitly included in the data

item for losses.

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Oil

6.50. For products classified in SIEC under Section 4 – Oil, the following list of additional data

items applies.

Item

number

Data item

4.1 Backflows from petrochemical industry to refineries

4.2 Refinery intake (by products)

4.3 Refinery losses

4.4 Direct use (of crude oil, NGL, etc.)

6.51. Backflows from petrochemical industry to refineries consist of finished or semi-finished

products which are returned from energy consumers to refineries for processing, blending or sale.

They are usually by-products of petrochemical manufacturing. For integrated petrochemical

industries, this flow should be estimated. Transfers from one refinery to another within the country

are not covered by this data item.

6.52. Refinery intake refers to the amount of oil (including other hydrocarbons and additives) that

has entered the refinery process.

6.53. Refinery losses refer to losses during the refinery processes. They are the difference

between refinery intake (observed) and the production from refineries (gross refinery output).

Losses may occur, for example, during the distillation processes due to evaporation. The reported

losses are shown as a positive number in a mass balance. Although there may be volumetric gains,

there are no gains in mass.

6.54. Direct use refers to the use of crude oil, NGL and other hydrocarbons directly without being

processed in oil refineries. This includes, for example, crude oil burned for electricity generation.

Electricity and Heat

6.55. For products classified in SIEC under Section 7 (Electricity) and Section 8 (Heat), the

following list of additional data items applies.

Item

number Data item

5.1 Gross Production (by type of producer, by type of plant and

by production process)a

5.2 Own Use

5.3 Net Production (by type of producer, by type of plant and by

production process) a

5.4 Use of energy products (by energy products and by

transformation processes) a See Section D.1 in Chapter 5 for a list of types of producers, types of plant and production processes.

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6.56. Gross electricity production is the sum of the electrical energy production by all generating

units/installations concerned (including pumped storage) measured at the output terminals of the

generators.

6.57. Gross heat production is the total heat produced by the installation and includes the heat

used by the installation’s auxiliaries which use a hot fluid (liquid fuel heating, etc.) and losses in

the installation/network heat exchanges, as well as heat from chemical processes used as a primary

energy form. It should be reminded that for autoproducers, the production of heat covers only the

heat sold to third parties; thus gross heat production for autoproducers is equal to net heat

production.55

6.58. Net electricity production is equal to the gross electricity production less the electrical

energy absorbed by the generating auxiliaries and the losses in the main generator transformers.

6.59. Net heat production is the heat supplied to the distribution system as determined from

measurements of the outgoing and return flows.

6.60. Own use is defined as the difference between the gross and the net production.

6.61. Use of energy products (by energy product and by transformation processes) refers to the

quantity of energy products used for the generation of electricity and heat.

3. Data items on production, storage and transmission capacity

6.62. The data items presented in this section refer to the production, storage and transmission

capacity of energy. These statistics are important for the assessment of the ability of a country to

produce and store energy products, as well as to transmit and distribute electricity.

Natural gas

Item

number Data item

6.1 Peak output

6.2 Gas storage facility – Name

6.3 Gas storage facility – Type of storage

6.4 Gas storage facility – Working capacity

6.63. Peak output. Peak output is the maximum rate at which natural gas can be withdrawn from

storage.

6.64. Name of storage facility. The name of the storage facility identifies the facility. Additional

information on the location or site of the facility is also important for its proper identification.

55 See Table 5.2.

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6.65. Type of storage capacity. There are three main types of storage in use: (a) Depleted oil and

gas fields that are naturally capable of containing the gas and have installations for the injection

and withdrawal of the gas; (b) Aquifers which may be used as storage reservoirs provided that they

have suitable geological characteristics (e.g. the porous sedimentary layer must be overlaid by an

impermeable cap rock); and (c) Salt cavities that may exist naturally or be formed by injecting

water and removing the brine. Salt cavities are generally smaller than the reservoirs provided by

depleted oil and gas fields or aquifers but offer very good withdrawal rates and are well suited for

peak-shaving requirements.

6.66. Working capacity. Working capacity is the total gas storage capacity minus cushion gas.

(“Cushion gas” refers to the volume of gas required as a permanent inventory to maintain adequate

underground storage reservoir pressures and deliverability rates throughout the output cycle).

Oil

Item

number Data item

6.5 Refinery capacity

6.67. Refinery capacity is the theoretical maximum capacity of crude oil refineries available for

operation at the end of the reference period. For annual data, capacity should be measured where

possible on 31 December.

Biofuels and waste

Item

number Data item

6.6 Liquid Biofuel Plant Capacity

6.6.1 Biogasoline Plant Capacity

6.6.2 Biodiesel Plant Capacity

6.6.2 Other Liquid Biofuel Plant Capacity

6.68. Liquid biofuel plant capacity refers to the production capacity available for operation at the

end of the reference period in terms of tons of products per year (for annual data). This information

is disaggregated according to the type of plant.

Electricity and heat plants

Item

number Data item

6.7 Net maximum electrical capacity (by type of technology)

6.8 Peak load demand

6.9 Available capacity at time of peak

6.10 Date and time of peak load occurrence

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6.69. Net maximum electrical capacity is the maximum active power that can be supplied

continuously (i.e., throughout a prolonged period in a day with the whole plant running) at the

point of outlet (i.e., after taking the power supplies for the station auxiliaries and allowing for the

losses in those transformers considered integral to the station). This assumes no restriction of

interconnection to the network. It does not include overload capacity that can only be sustained for

a short period of time (e.g., internal combustion engines momentarily running above their rated

capacity).

6.70. Peak load demand is the highest simultaneous demand for electricity satisfied during the

year. Note that the electricity supply at the time of peak demand may include demand satisfied by

imported electricity, or alternatively, the demand may include exports of electricity. Total peak

load on the national grid is not the sum of the peak loads during the year at every power station as

they may occur at different times. Either synchronized or very frequent data must be available in

order to measure the peak load demand. The former is likely to be gathered by the national grid

authority, and the latter by some electricity-generating companies.

6.71. Available capacity at time of peak of an installation is the maximum power at which it can

be operated under the prevailing conditions at the time, assuming no external constraints. It

depends on the technical state of the equipment and its ability to operate and may differ from the

net maximum capacity, e.g. due to lack of water for hydro capacity, plant maintenance,

unanticipated shutdown, or other outages at the time of peak load.

6.72. Date and time of peak load occurrence consist of the date and time on which the peak load

was reached.

4. Data items for assessment of economic performance

6.73. Data items for the assessment of the economic performance of producers and users of

energy are important economic indicators that allow for the formulation and monitoring of

economic policies related to energy (e.g., impact of taxation on consumers’ behaviour, contribution

of the energy industry to the national gross domestic product, etc.). The data items presented below

are closely linked with the concepts, definitions and methods of the 2008 System of National

Accounts (2008 SNA).

6.74. The data items presented in this section are generally collected as part of economic

statistics, thus further reference and detail are provided in the International Recommendations for

Industrial Statistics 2008.

Item

Number Reference List Items

7.1 Consumer prices (end-use) (by energy product)

7.2 Import energy prices (by energy product)

7.3 Export energy prices (by energy product)

7.4 Taxes (by energy product)

7.5 Other taxes on production (by energy product)

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7.6 Subsidies received (by energy products)

7.7 Subsidies on products (by energy product)

7.8 Other subsidies on production (by energy product)

7.9 Gross output at basic prices

7.10 Of which: of energy products (by product)

7.11 Total number of persons employed

7.12 Average number of persons employed

7.13 Hours worked by employees

7.14 Gross fixed capital formation

6.75. Prices refer to the actual market price paid for an energy product (or group of products).

They correspond to what is commonly referred to as spot prices. Consumer prices refer to

“purchasers’ prices” (2008 SNA, paragraph 14.46), which are the amount paid by the purchaser.

For analytical purposes, countries are encouraged to compile information on the components of

the different prices:

Producers’ prices =

Purchasers’ prices

- Wholesale and retail distribution margins (trade margins)

- Transportation charges invoiced separately (transport margins)

- non-deductible value added tax (VAT)

and

Basic prices =

Producers’ prices

- Taxes on products resulting from production, excluding invoiced VAT

- Subsidies on products resulting from production

6.76. Import prices generally include cost, insurance and freight (CIF) at the point of entry into

the importing economy.

6.77. Export prices are valued free on board (FOB) at the point of exit from the exporter’s

economy. It includes the cost of transport from the exporter’s premises to the border of the

exporting economy.

6.78. Taxes are compulsory unrequited payments, in cash or in kind, made to the government.

Two main groups of taxes are identifiable: taxes on products; and other taxes on production.

However, only other taxes on production are presented as data item as these payments are recorded

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in the business accounts of units. It is recommended that, in statistical questionnaires, countries

refer to the specific names or descriptions of taxes as they exist in their national fiscal systems.

6.79. Other taxes on production are taxes that units are liable to pay as a result of engaging in

production. As such, they represent a part of production costs and should be included in the value

of output. Units pay them irrespective of profitability of production. These taxes consist mainly of

taxes on the ownership or use of land, buildings or other assets used in production, or on the labour

employed or compensation of employees paid. Examples of such taxes are motor vehicle taxes,

duties and registration fees, and levies on the use of fixed assets. Also included are official fees and

charges (i.e. duties payable for specific public services, such as the testing of standards of weights

and measures, provision of extracts from official registers of crime and the like).

6.80. It may not be possible to collect data on all these taxes at the establishment level; therefore,

in such cases the design of statistical questionnaires and subsequent data compilation should

clearly indicate the type of taxes that have been reported.

6.81. Subsidies received covers payments that government units make to resident producing units

on the basis of their production activities or the quantities or values of the goods or services they

produce, sell or import. The classification of subsidies follows closely the classification of taxes.

6.82. Subsidies on products correspond to subsidies payable per unit of a good or service

produced, either as a specific amount of money per unit of quantity of a good or service, or as a

specified percentage of the price per unit; it may also be calculated as the difference between a

specified target price and the market price actually paid by a buyer.

6.83. Other subsidies on production consist of subsidies, except subsidies on products that

resident enterprises may receive as a consequence of engaging in production (for example,

subsidies on payroll or workforce and subsidies to reduce pollution).

6.84. Gross output at basic prices measures the result of the overall production activity of

economic units. The value of production corresponds to the sum of the value of all goods or

services actually produced within an establishment and made available for use outside that

establishment, plus any goods and services produced for own final use. In order to maintain

consistency with the valuation principles for output (production) of other international

recommendations on business statistics and national accounts, it is recommended that countries

compile the output of establishments at basic prices. However, in circumstances where it is not

possible to segregate “taxes and subsidies on products” and “other taxes on production”, valuation

of output at factor cost can serve as a second best alternative.

6.85. Gross output of energy products (by product) refers to the output generated by the

producing unit for each of the energy products described in SIEC.

6.86. Total number of person employed, average number of persons employed, and hours worked

by employees are important data items describing, for example, the contribution of the energy

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industry to total employment, as well as allowing for the assessment of labour input and labour

efficiency in energy production.

6.87. Gross fixed capital formation is measured by the total value of a producer’s acquisitions,

less disposals, of fixed assets during the accounting period, plus certain specified expenditures on

services that add to the value of non-produced assets. It should include the value of all durable

goods expected to have a productive life of more than one year and intended for use by the

establishment (land, mineral deposits, timber tracts and the like, buildings, machinery, equipment

and vehicles). This data item is a measure of the investments of an economic entity and should be

disaggregated by type of asset to provide a basis for a more comprehensive evaluation of the

performance of energy industries.

5. Data items on mineral and energy resources

6.88. Data items on mineral and energy resources are important for the assessment of their

availability in the environment, as well as for the assessment of their depletion. This information is

often used in the compilation of asset accounts in the SNA, as well as in the System of

Environmental-Economic Accounting for Energy (SEEA-Energy). This section is based on the

work that has been carried out in the preparation of SEEA-Energy.

6.89. The mineral and energy resources relevant for energy statistics and accounts are a subset of

the resources defined in the SEEA Central Framework and comprise the following:

Table 6.1: Mineral and energy resources relevant for energy56

Oil resources

Natural Gas resources

Coal and peat resources

Uranium and other nuclear fuels

6.90. The United Nations Framework Classification for Fossil Energy and Mineral Reserves and

Resources (UNFC 2009) provides a scheme for classifying and evaluating these resources

according to three dimensions, namely, their economic and social viability, the field project status

and feasibility, and the geological knowledge about these resources. SEEA-Energy groups the

detailed categories of UNFC into three aggregated classes characterizing the commercial

recoverability of the resources as follows:57

Table 6.2: Categorization of mineral and energy resources relevant for energy

Class A: Commercially recoverable resources

Class B: Potentially commercially recoverable resources

56 See SEEA-Energy, Table 2.5.

57 See SEEA-Energy, Table 5.1 for the definition of these categories in terms of UNFC 2009.

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Class C: Non-commercial and other known deposits

6.91. The data items on mineral and energy resources consist of the items presented below

covering the opening and closing stock levels of the energy resources by type of resources (oil

resources, natural gas resources, etc.) and by type of characteristics (commercially recoverable,

etc.).

Item

number Data item

8.1 Opening stocks of mineral and energy resources (by type of resources and by type of characteristics)

8.2 Closing stocks of mineral and energy resources

(by type of resources and by type of characteristics)

6.92. The opening and closing stocks of mineral and energy resources58

refer to the amount of

the resource at the beginning and end of the reference year by type of resources (as classified in

Table 6.1) and type of characteristics (as classified in Table 6.2).

6.93. It should be noted that these data are generally estimated by geological institutes through

geological modelling and not directly collected by the statistical agency in charge of the

compilation of energy statistics.

58 It is important to note that the term “stocks” is here understood as in the context of SEEA and SNA, where it is used

to designate any point-in-time accumulation within the economy, whether they are mineral and energy resources or

energy products. What is called “stocks” in energy statistics is referred to as “inventories” in the context of SNA and

SEEA.

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Chapter 7. Data collection and compilation

7.1. Energy data collection and compilation are difficult tasks and country practices in this

respect vary significantly. Countries should make efforts to learn from the experiences of

others, share best practices and promote relevant standards and strategies that will improve the

overall quality of energy data, including their completeness and international comparability. To

assist countries in these activities, this chapter discusses the role of legal frameworks and

institutional arrangements in data collection, followed by a discussion of data collection

strategies, data sources and data compilation methods.

A. Legal framework

7.2. The existence of a strong legal framework is one of the most important prerequisites for

establishing a sound national statistical system in general and a national system of energy

statistics in particular. The legal framework is provided by statistical laws and other applicable

national laws and regulations which, to different degrees, specify the rights and responsibilities

of entities that collect data, provide data, produce statistics, or use statistical outputs. For

example, data obtained by conducting statistical surveys depend on statistical laws and energy

related legislation and regulations, while data on imports and exports of energy are subject to

customs laws and regulations.

7.3. The establishment of a legal framework to make reporting of energy data mandatory

through well designed channels and instruments is of great importance for ensuring the

compilation of high quality energy statistics. Although many countries lack such a legal

framework, it is important to recognize it as the preferred option. For such a framework, energy

ministries or energy agencies maintain administrative records relevant to energy statistics,

while national statistical offices organize data collection from entities that produce energy

products as a primary or secondary activity and from energy users. The legal framework should

not only enable efficient data collection but deal adequately with confidentiality issues,

providing necessary protection to data reporters (See Chapter 10 for further discussion of

confidentiality.).

7.4. The legal framework should also describe responsibilities for collection, compilation

and maintenance of the different data components among different government bodies, taking

into account the variety of public policy objectives, and the changes brought about by market

liberalization that often increase the difficulty in obtaining data given the growing number of

participants in energy industries and the commercial sensitivities around data disclosure in an

ever more competitive market.

7.5. It is recommended that national agencies responsible for the compilation and

dissemination of energy statistics should, whenever appropriate, actively participate in the

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discussions on national statistical legislation or relevant administrative regulations in order to

establish a solid foundation for high quality and timely energy statistics, with a view to

mandatory reporting, whenever appropriate, and adequate protection of confidentiality. Also,

such participation would strengthen the agencies’ responsiveness to the data requirements and

priorities of the user community.

B. Institutional arrangements

7.6. The legal framework creates a necessary, but not sufficient, foundation for energy

statistics. To ensure that these statistics are collected and compiled in the most effective way,

establishing appropriate institutional arrangements among all relevant governmental agencies is

of paramount importance.

7.7. Members of a national system of energy statistics. A national system of energy statistics

consists of various governmental agencies engaged in the collection, compilation and

dissemination of energy statistics. The most important members of such a system are national

statistical offices and specialized governmental agencies responsible for the implementation of

energy policies (e.g., energy ministries). However, the complex and vast nature of energy

supply and use, and the liberalization of the energy markets in many countries have resulted in

an increasing number of governmental agencies and other organizations collecting data and

maintaining databases on energy, such as chambers of commerce, industry associations,

regional offices, etc. This represents, on the one hand, a great potential for reducing the

response burden and improving timeliness of the data, but on the other, poses great challenges

in ensuring the harmonization of data as the underlying concepts, definitions, methods and

quality assurance applied by different agencies might vary significantly.

7.8. Purposes of institutional arrangements. To function efficiently, a national system of

energy statistics should be based on appropriate institutional arrangements among many

relevant agencies. Such arrangements should allow for the collection, compilation,

standardization and integration of information scattered among different entities and for the

dissemination of the compiled statistics to users through a coherently networked information

system or a central energy database. The institutional arrangements should also promote

harmonization with international standards and recommendations to enable the collection of

high quality and internationally comparable official energy statistics. Last but not least,

efficient institutional arrangements will not only minimize the data collection cost for agencies

involved by avoiding duplication of work and enabling the sharing of good practices, but will

also result in a reduced response burden on data reporters due to improved communication and

coordination among data collectors.

7.9. Governance of the national system of energy statistics. A key element of the

institutional arrangements is the establishment of a clear, efficient and sustainable system of

governance of the national system of energy statistics. Depending on a country’s legislation

and other national considerations, various agencies might lead the system and be responsible

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for official energy statistics. These can be national statistical offices, energy ministry or agency,

or another specialized governmental agency. It is imperative that the lead agency ensures the

necessary coordination of work, thus resulting in energy statistics that comply with the quality

standards as described in Chapter 10.

7.10. Mechanism for functioning of the system. In order to guarantee the successful

functioning of a national system of energy statistics, it is vital that all stakeholders are actively

involved. It is recommended that countries develop an appropriate interagency coordination

mechanism which, while taking into account existing legal constraints, would systematically

monitor performance of the national system of energy statistics, motivate its members to

actively participate in the system, develop recommendations focused on improving the

system’s functioning, and have the authority to implement such recommendations. Such a

mechanism should address, among others, the issue of statistical capacity, as the lack of

funding and human resources is a persistent problem in many countries. In this context, the

proper allocation of responsibilities to agencies, as well as the convening of joint training

courses and workshops on energy matters to further develop the skills and knowledge of the

staff, can be of great help.

7.11. Models for the organization of a national system of energy statistics vary from a

centralized system, in which one institution is in charge of the whole statistical process (from

the collection, compilation to the dissemination of statistics), to a decentralized system, in

which several institutions are involved and are responsible for different parts of the process or

different components of energy statistics.

7.12. It is recognized that different institutional arrangements (depending on the structure of a

country’s government, legal framework and other national considerations) can result in high

quality energy statistics, provided that the overall national system follows internationally

accepted methodological guidelines, utilizes all available statistical sources and applies

appropriate data collection, compilation and dissemination procedures. Effective institutional

arrangements are usually characterized by:

(a) The designation of only one agency responsible for the dissemination of official

energy statistics or, if this is not possible, the identification of agencies responsible

for the dissemination of specific data subsets and mechanisms that will ensure

overall consistency of energy statistics;

(b) A clear definition of the rights and responsibilities of all agencies involved in data

collection and compilation;

(c) The establishment of formalized working arrangements between them, including

agreements on holding inter-agency working meetings and on access to relevant

micro data collected by those agencies. The formal arrangements should be

complemented by informal agreements among the involved agencies and institutions

as required.

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7.13. It is recommended that countries consider the establishment of the institutional

arrangements necessary to ensure the collection and compilation of high quality energy

statistics as a matter of high priority and periodically review their effectiveness.

7.14. Whatever the institutional arrangement, the national agency that has the overall

responsibility for the compilation of energy statistics should periodically review the definitions,

methods and the statistics themselves to ensure that they comply with relevant international

recommendations and recognized best practices, are of high quality, and are available to users

in a timely fashion. If such an agency is not designated, then an appropriate mechanism should

be put in place to ensure that those functions are performed consistently and effectively.

C. Data collection strategies

7.15. The collection of energy data can be a complex and costly process, which very much

depends on a country’s needs and circumstances, including the legal framework and

institutional arrangements. Therefore, it is important that countries undertake it on the basis of

well thought out strategic decisions regarding the scope and coverage of data collection,

organization of the data collection process, selection of the appropriate data sources and use of

reliable data collection methods.

1. Scope and coverage of data collection

7.16. The scope and coverage of the collection of energy statistics are defined according to:

a. Conceptual design, which includes the objective and thematic coverage

b. Target population

c. Geographical coverage

d. Reference period of data collection

e. Frequency with which data are to be collected

f. Point in time of collection

7.17. Conceptual design. The overall objective of the data collection should be clearly

defined. The thematic coverage must take into account the type of statistics to be collected, for

example, the flows and stocks of energy products and the units of measurement. International

standards should be applied in the conceptual design process.

7.18. Target population. Good knowledge of the main groups of data reporters is required for

an efficient data collection, so that data collection methods can be customized as necessary. It

is recommended, as applicable, that at least the following three reporter groups be

distinguished: energy industries, other energy producers and energy consumers.

7.19. Energy industries (see Chapter 5 for definition) are represented by various entities

whose principal activity is directly related to energy production and which often concentrate on

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one particular fuel or one part of the overall energy supply chain. Detailed information is

compiled by the energy industry entities themselves on a regular basis for management

purposes, as well as for reporting to government regulatory bodies. Therefore, statistical data

can often be obtained from those entities directly or from administrative records maintained by

regulatory bodies without too much delay, when the proper data collection mechanisms exist.

7.20. The entities belonging to the energy industries can be differentiated, according to their

ownership status, as private industries, public industries and public-private industries. The

degree to which a central government is directly involved in the industries can have a

significant effect on both the ease with which data may be collected, and the range of data that

will be considered reasonable to collect. Given that such industries can provide data on most

energy flows, they need to be treated with special attention and be fully enumerated in

statistical surveys or covered using appropriate administrative sources (see section on data

sources for details). When the number of energy industry entities is large and the energy

statistics compiler has no direct contact with the original sources, it is common for industrial

associations, regional offices or civil organizations to act as intermediate data collectors and

reporters to simplify the data collection process. However, in such a case, efforts should be

undertaken to ensure that data quality is not compromised.

7.21. Other energy producers include those economic units (including households) that

produce energy for self-consumption; they may sometimes supply it to other consumers, but

not as part of their principal activity (see Chapter 5 for details). Since these activities are not

the principal objective of these companies and since they may be partially or fully exempt from

the provisions of energy legislation and regulations, it cannot be expected that they will have

the same amount of detailed information readily.

7.22. Even though in most cases other energy producers account for only a small part of the

national energy production, it is important that they are included in national energy statistics to

properly account for their energy needs and measure their energy efficiency. In countries where

other energy producers play a significant role in the national aggregate of energy supply and

consumption, appropriate procedures have to be devised to obtain more adequate data from

them. In some countries, the auto-production of electricity and heat (see Chapter 5 for details)

requires governmental authorization, which facilitates the monitoring of these companies and

creates the means for obtaining the required data.

7.23. Energy consumers can be grouped according to the energy needs of the economic

activity under which they are classified, such as industry, households, etc. (See Chapter 5 for

details.) Data collection from energy consumers is complex since it has to take into account

their diversity, mobility and multipurpose forms. To facilitate this task, specific methodologies

and compilation strategies must be designed for the different subgroups of consumers, given

their particularities.

7.24. It is usually the case that energy producers can provide data on how much energy in

total is being delivered to energy consumers, and often may also be able to provide a

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breakdown of total deliveries by the various consumer groups taking into account differences

in applicable tariffs and/or taxes. However, in order to fill the remaining data gaps and obtain

more detailed information (e.g., in the case of energy balance compilation), direct consumer

surveys might be necessary. The coherence between data based on the information about

energy deliveries to final consumers and the information reported by consumers must be

ensured. In some other cases, for example solid biomass fuels, information will most likely be

obtained through surveys and consumer-derived measurements, rather than from energy

producers, thus avoiding potential producer-consumer data mismatch.

7.25. Collection of energy data from the informal sector. The informal sector has been defined

by the fifteenth International Conference of Labour Statisticians59

according to the types of

production units of which it is composed. It consists of a subset of household unincorporated

enterprises, with at least some production for sale or barter, operating within the production

boundary of the System of National Accounts (SNA). As household production units, these

enterprises do not constitute separate legal entities independent of the households or household

members that own them, and no complete sets of accounts (including balance sheets of assets

and liabilities) are available that would permit the production activities of the enterprises to be

clearly distinguished from the other activities of their owners, nor any flows of income and

capital between the enterprises and the owners to be identified.

7.26. An energy producing unit in the informal sector may be defined as a household

enterprise with at least some production of energy for sale or barter that meets one or more of

the following criteria: limited size in terms of employment; non-registration of the enterprise;

and non-registration of its employees. The informal sector thus defined excludes household

enterprises producing energy exclusively for own final use. The area-based enterprise survey

approach is commonly used to collect data from such enterprises, as a satisfactory list of such

enterprises is normally not available.60

7.27. Geographical coverage. The geographical coverage identifies the area for which the

statistics are collected. In general, for policy purposes it is fundamental to collect statistics at

the national level. However, for analytical and policy-making purposes it is often the case that

countries compile their energy statistics at a subnational level, which implies a more detailed

geographical coverage. The collection of energy statistics at the subnational level is often

essential in planning future infrastructure, as it allows the different locations of production and

consumption to be taken into account. Where consumption is concerned, regional

59 Resolution concerning statistics of employment in the informal sector, adopted by the Fifteenth International

Conference of Labour Statisticians (January 1993). Available from

http://www.ilo.org/public/english/bureau/stat/download/res/infsec.pdf.

60 For details on issues such as the identification of statistical units applicable in the case of the informal sector and the

organization of surveys of the informal sector, see the International Recommendations for Industrial Statistics (UN

2009b) (Chapter 2, section F, and Chapter 6).

113

disaggregation is necessary since energy use could vary significantly according to climate,

local behaviour, customs, economic activities, incomes, availability of energy products, etc.

The collection of such detailed information often implies a higher data collection cost and

requires additional methodological efforts to ensure that there are no omissions or double

counting in the results when collating regional data up to the national level.

7.28. Reference period of data collection. The reference period of the energy data collected

refers to the time period that the data relate to. For example, oil production data may have a

reference period of one month, energy use data collected from households may have a

reference period of one quarter and energy behaviour data (e.g., data on measures taken to

reduce energy use) may have a reference period of one year.

7.29. Frequency of data collection. The frequency of collection of energy data adopted by a

given country is the result of a balance between users’ needs, the priority given to timeliness of

particular data items, the level of detail required, the availability of data and the available

resources. Comprehensive annual data should be the initial objective when setting up an energy

statistics programme. However, higher frequency (infra-annual) collections are critically

important for the timely assessment of a fast changing energy situation and countries are

encouraged to conduct them on a regular basis within the identified priority areas of energy

statistics. The various frequencies of data collection are further outlined below.

Annual data collections. These collect energy data relating to the basic and most

appropriate information needs. In general, they cover production, supply and consumption

at a detailed level of disaggregation for any energy products that make up a significant

share of total energy supply.

Infra annual data collections (quarterly, monthly, etc.). These are conducted when the need

for frequent data is of high priority (e.g., monthly oil production and trade) but are usually

more restricted in the level of detail (for example, total consumption rather than

consumption by consumer groups) than those collections carried out annually, as higher

frequency leads to increased costs and reporting burden.

Infrequent data collections (less frequent than annual). These are generally conducted by

countries, either for specialized topics (e.g. deployment of fuel cells), to fill in gaps in the

data collected annually or infra-annually (e.g. more accurately ascertaining sub-sector

breakdowns of minor products), to provide baseline information, or where data collection is

particularly expensive (e.g., large consumer surveys or censuses).

7.30. Point in time of collection. The point in time when the collection is carried out should

also be carefully considered, since this may have an impact on the response rate (e.g., avoid

sending questionnaires during holiday periods, overlap with other surveys, as well as with

administrative data collections such as tax filing).

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2. Organization of data collection

7.31. Proper organization of the data collection process is fundamental for official energy

statistics. The first important step in data collection is to identify the production, supply,

transformation and consumption flows for each fuel in order to clarify the processes,

procedures and the statistical units involved. Then it is necessary to outline the potential data

sources for each flow to determine whether it is feasible to obtain accurate information on a

regular basis from them, making use of the information they already hold for their own

management purposes. From these descriptions, it can be determined what kind of energy data

can be obtained from different sources, and the process can be planned accordingly.

7.32. In general, data collection relies on the legal framework and institutional arrangements

of the country, as well as on the use of agreed collection methods, such as the use of statistical

business registers, administrative data and census or sample surveys, to obtain comprehensive

data. The most appropriate collection method should be selected, taking into consideration the

nature and specific characteristics of the given energy activity, the availability of the required

data, and the budget constraints that might affect the implementation of the collection strategy.

7.33. An integrated approach to collection of energy statistics. The collection of energy data

should be seen as an integral part of the data collection activities of the national statistical

system in order to ensure the best possible data comparability and cost efficiency. In this

context, close collaboration between energy statisticians and compilers of industrial statistics,

as well as statisticians responsible for conducting household, labour force and financial

surveys, is of paramount importance and should be fully encouraged and systematically

promoted. A collaborative relationship will create a better understanding of the information,

provide an opportunity to incorporate energy items into non-energy specific questionnaires,

taking into account the priorities and specific needs of the energy industries, and facilitate the

conduct of a cost-benefit analysis.

7.34. The establishment or improvement of the regular programme of energy data collection

should be part of a long-term strategic plan in the area of official statistics. Such a programme

should be properly designed and executed in order to obtain the widest possible coverage and

ensure the collection of accurate, detailed and timely energy statistics.

7.35. An integrated approach is especially important for the collection of data on energy

consumption, as many different data sources can be used. Data can be obtained directly or

indirectly from appropriate economic units (i.e., enterprises or establishments and households)

by means of censuses, surveys and/or administrative records. Given that the number of energy

consumers is larger than energy suppliers, it may be necessary to exploit existing business

surveys to identify those establishments that will be required to answer specific questions on

energy consumption. Consistency of data on energy consumption collected from various

sources should be ensured.

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D. Data Sources

7.36. The generation of energy statistics is based on data collected from two main sources:

Statistical data sources that provide data collected exclusively for statistical purposes from

censuses and/or sample surveys; and

Administrative data sources that provide data created originally for purposes other than the

production of statistical data.

1. Statistical data sources

7.37. The typical statistical data sources for compiling energy statistics are surveys of the

units in the population under consideration. The surveys are done either by enumerating all the

units in the population (census) or a subset of representative units scientifically selected from

the population (sample survey).

7.38. In general, censuses represent a time consuming, resource intensive and costly exercise

for the collection of energy statistics and imply a high overall response burden on the

population. For these reasons, it is unlikely that censuses will be used very often. However,

depending on the population of interest, the available resources and the particular

circumstances in a country, conducting a census may be a viable option for collecting energy

statistics. A complete census of units in the energy industry may be appropriate when, for

example, a particular country does not maintain an up-to-date business register, there are few

energy producers (in such a case they should be included in a “take all” stratum of appropriate

surveys), or there is significant user interest for detailed energy data.

7.39. Sample surveys are used to collect information from a portion of the total population,

called a sample, in order to draw inferences on the whole population. They are almost always

less costly than censuses. There are different types of surveys that can be used in energy

statistics depending on the sampling units: (i) enterprise surveys, (ii) household surveys and

(iii) mixed household-enterprise surveys. In general, it is recommended that countries make

efforts to establish a programme of sample surveys that would satisfy the needs of energy

statistics in an integrated way (i.e., as part of an overall national sample survey programme of

enterprises and households) to avoid duplication of work and minimize the response burden.

Survey design

7.40. Before carrying out a survey, it is fundamental to have a proper survey design. To

achieve this goal a number of steps are needed. First, the particular information needs should

be identified and the specific goals of the project established, placing special emphasis on

priorities, feasibility, budget, geographic breakdown, etc. In order to do so, it is necessary to

make use of the experience gained in similar projects in other areas of statistics, and take into

account relevant international recommendations (e.g., those published in International

Recommendations for Industry Statistics 2008) and the provisions of relevant applicable

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national laws and regulations. This phase requires the expertise of professionals in the specific

subject area being covered, such as specialists in energy matters, as well as specialists in

sample design, interviewing techniques, analysis procedures, etc. Given the above,

participation and cooperation among national statistical office, different ministries and

academic institutions are crucial.

7.41. Ideally, energy surveys must be designed to ensure their regular conduct. For this

reason, it is recommended that the periodicity of such surveys be established from the very

beginning. Countries are encouraged to ensure that the survey design is optimized, keeping in

mind the desirable use and inferences from the expected results, while information not essential

for the survey purposes should be avoided as much as possible. Considering the cost of

conducting such surveys, the survey must be designed in such a way as to guarantee the

greatest benefits from the analytical results and ensure their consistency over time.

7.42. Once the specific topic(s) of the survey are determined, the next stage is to select the

data items using those presented in Chapter 6 as the reference list and ensuring that the

selection is done according to an appropriate classification and precise definition of each of the

concepts used in the data items definitions.

7.43. Selecting the target population or sample is critical to successfully meet the goals of the

survey. Within this phase, the number of units to be interviewed must be decided in order to

ensure representativeness, taking into account the time availability, budget constraints and

necessary degree of precision. The sampling technique used will depend on the population or

populations being sampled, as well as on the information available from other regular survey

programmes and business registers that may provide a better picture and context of the project

being considered.

7.44. The design of the questionnaires and supplementary documentation should follow.

Deciding on the interviewer’s profile, the interviewing method best suited for the survey’s

purpose (personal interviews, telephone surveys, mail surveys, computer direct interviews,

email surveys, Internet surveys and others), the temporal scope of the data items and the way

each of them and related concepts will be presented and asked are essential for good

questionnaire design. Determining the type of questions and their sequence comes next, paying

special attention to using clear, direct and straightforward language. The use of proper

measurement units in terms of which the answers should be provided is also very significant

and depends largely on who is being interviewed. For example, small units of measurement

such as kilowatt-hour, cubic metre, etc., are perfectly proper for consumers or gasoline stations,

but not for energy supply industries.

7.45. Another important part of the survey design is the preparation of concise and clear

instructions to help clarify any questions that potential respondents might have. It is important

to mention that the survey design should be adapted as required according to the specific

context, geographical scope, informant, interviewer and the planned procedures. The

questionnaires must be tested in a context similar to the one in which they will be applied prior

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to the finalisation of the required adjustments. For example, interviewers need to be carefully

trained in the techniques to be used for measuring different fuels. In some cases, especially for

measuring biomass, the availability of measurement instruments (e.g., scales for fuelwood and

charcoal) for the physical measurement of fuels actually consumed is extremely important and

should be ensured where possible.

Enterprise surveys

7.46. Enterprise surveys are surveys in which the sampling units comprise enterprises (or

statistical units belonging to these enterprises such as establishments or kind-of-activity units)

in their capacity as the reporting and observation units from/about which data are obtained.

They assume the availability of a sampling frame of enterprises. Depending upon the source of

the sampling frame, such surveys may also be classified as either list based or area based. In a

list-based survey, the initial sample is selected from a pre-existing list of enterprises or

households. In an area-based survey, the initial sampling units are a set of geographical areas.

After one or more stages of selection, a sample of areas is identified within which enterprises

or households are listed. From this list, the sample is selected and data collected. In general, it

is preferred to use list-based surveys as it may be difficult to enumerate the enterprises within

an area, and area-based sampling is inappropriate for (large or medium-sized) enterprises that

operate in several areas because of the difficulty of collecting data from just those parts of the

enterprises that lie within the areas actually selected. A stratified sampling technique should be

used whenever appropriate and feasible to improve accuracy of data.

7.47. Use of business register. In principle, the sampling frame should contain all the units

that are in the survey target population, without duplication or omissions. The business register

maintained by countries for statistical purposes provides such a population. In general, a

statistical business register is a comprehensive list of all enterprises and other units, together

with their characteristics, that are active in a national economy. It is a tool for conducting

statistical surveys, as well as a source for statistics in its own right. The establishment and

maintenance of a statistical business register in most cases are based on legal provisions, as its

scope and coverage are determined by country-specific factors. It is recommended, as the best

option, that the frame for every list-based enterprise survey for energy industries be derived

from a single general-purpose statistical business register maintained by the statistical office,

rather than from stand-alone registers for each individual survey.

7.48. For countries not maintaining an up-to-date business register, it is recommended that

the list of enterprises drawn from the latest economic census and amended as necessary, based

on relevant information from other sources, be used as a sampling frame.

Ad hoc energy statistics surveys

7.49. Specially designed energy statistics surveys are extremely useful to compensate for the

lack of information and gaps associated with the mechanisms and instruments mentioned

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above. Examples of ad hoc energy statistics surveys are energy consumption surveys designed

specifically to measure the quantities of energy products consumed. The sampling unit is likely

to be the household and possibly sites of small-scale rural industries below the normal

threshold for sample enquiries. Data generally cover the weights (or volumes, if realistic

conversions to weight can be made later) of different fuels consumed for different purposes. If

there is a seasonal pattern of fuel usage, interviews will have to be spread over the entire year

in order to be representative of all seasons. Results will need to be analysed by size of

household in order to obtain a range of per capita consumption figures.

7.50. The design and implementation of such surveys may be demanding in terms of financial

and human resources and often require multidisciplinary expertise in order to identify the

appropriate sample design, interviewing techniques and analysis procedures. In general, ad hoc

energy statistics surveys are very useful instruments for assessing energy consumption

activities, monitoring the impacts of energy programmes, tracking the potential for energy

efficiency improvements and targeting the feasibility of future programmes.

Household surveys and mixed household-enterprise surveys

7.51. Household surveys are surveys in which the sampling units are the households. In

mixed household-enterprise surveys, a sample of households is selected and each household is

asked whether any of its members own and operate an unincorporated enterprise (also called

informal sector enterprise in developing countries). The list of enterprises thus compiled is

used as the basis for selecting the enterprises from which desired data are finally collected.

Mixed household-enterprise surveys are useful for covering unincorporated (or household)

enterprises which are numerous and cannot be easily registered.61

7.52. Even though household surveys are not designed specifically for energy data

compilation, they can give a broad overview of residential energy consumption by end-use and,

potentially, of energy production by households. Given the complexity of energy consumption

characteristics in households, estimates and other measurements of energy consumption should

be derived from such surveys, using the metadata provided by them. For energy purposes,

useful information is related to the number and average size of households, appliance

penetration and ownership, appliance attributes and usage parameters, fuels used for cooking

and for heat and air conditioning, electricity sources (national grid, solar electricity, auto-

production, etc.), and types of bulbs used for illumination, etc. It is to be noted that the

characteristics of household appliances stock, such as age and efficiency, can also be

determined through the use of administrative registers or surveys on appliance sales.

7.53. The frequency of these household surveys is another key element in efforts to obtain

information on a regular basis, given that the behaviour in this sector often shows high

61 See IRIS 2008, paragraphs 6.19-6.24 for a description of advantages and disadvantages of mixed household-

enterprise surveys.

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variation due to changes in prices, technologies and fuel availability. The appearance on the

market of new household appliances creates new energy consumption habits that should be

taken into account.

7.54. These surveys should be representative not only at national level but also in rural and

urban areas and by regions in order to achieve a proper analysis of the data.

2. Administrative data sources

7.55. Publicly controlled administrative data sources. Data may be collected by diverse

governmental agencies in response to legislation and/or regulations to: (i) monitor activities

related to production and consumption of energy; (ii) enable regulatory activities and audit

actions; and (iii) assess outcomes of government policies, programmes and initiatives.

7.56. Each regulation/legislation (or related group of regulations/legislations) usually results

in a register of the entities (enterprises, households, etc.) bound by that regulation/legislation

and in data resulting from application of the regulation/legislation. The register and related data

are referred to collectively as administrative data. The data originating from administrative

sources can be effectively used in compiling energy statistics.

7.57. There are a number of advantages in the use of administrative data, the most important

of which include the following: reduction of the overall cost of data collection; reduction of the

response burden; smaller errors than those arising from a sample survey (due to the complete

coverage of the population to which the regulation/legislation applies); sustainability due to

minimal additional cost and long-term accessibility; regular updates; possible absence of a

survey design, sample measure and data editing; possibility of cooperation between various

agencies, which could lead to feedback on the compiling process and acknowledgment of

diverse areas of interest; potential data quality improvement; potential recognition of

administrative data uses; opportunity to link data from diverse sources; development of

statistical systems within agencies; and possible use as a framework for statistical surveys.

7.58. However, since administrative data are not primarily collected for statistical purposes, it

is important, when using such data, that special attention be paid to their limitations and efforts

made to ensure that their description is given in the relevant metadata. Possible limitations in

the use of administrative data include: inconsistencies in the concepts and definitions of data

items; deviation from the preferred definition of the statistical units; the legislation/regulation

may differ from the desired survey population; poor quality data due to lack of quality

assurance of the administrative data; possible breaks in the time series because of changes in

regulations/legislations; and legal constraints with respect to access and confidentiality. (See

Chapter 10 for further discussion of confidentiality.)

7.59. It is important that compilers of energy statistics identify and review the available

administrative data sources in their country and use the most appropriate ones for collecting

and compiling energy statistics. This significantly reduces the response burden and survey

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costs. The relative advantages and disadvantages mentioned above are not absolute. Whether

they apply and the extent to which they do depend on the specific country situation. Examples

of administrative data sources important for energy statistics include customs records (for

imports/exports of energy products), value added tax (VAT), specific taxes (or excise duty)

payable on specific fuels (gasoline and diesel for road use) or energy types (e.g., carbon tax),

and regulated electricity and gas market meter operator systems.

7.60. Privately controlled administrative data sources. Data may be collected by privately

controlled organizations, such as trade associations. This is typically done to assist the industry

in understanding important aspects of its own operations. These data are often also important to

government and decision- and policy-makers. The statistical agency responsible for energy

statistics should work cooperatively with these private organizations to gain access to such

data, in order to maximise their statistical value. This would keep the reporting burden on the

industry to a minimum, by not requiring the businesses to report to both the private

organization and the statistical agency. However, if agreement cannot be reached, the statistical

agency may need to require that the data be submitted to them directly. Every effort should be

made to establish proper cooperation between the private organizations and the statistical

agency. Statistical agencies must ensure the quality and objectivity of data being provided by

these organizations, as data collection is not their primary activity and they may be functioning

as industry advocates.

E. Data compilation methods

7.61. Data compilation, in general, refers to the operations performed on collected data to

derive new information according to a given set of rules (statistical procedures), with a view to

producing various statistical outputs. In particular, data compilation methods cover: (a) data

validation and editing; (b) imputation of missing data; and (c) estimation of population

characteristics. These methods are used to deal with various problems with collected data, such

as incomplete coverage, non-response, out of range responses, multiple responses,

inconsistencies or contradictions and invalid responses to questions. These problems may be

caused by deficiencies in the questionnaire design, lack of proper interviewer training, errors

by the respondent providing the data, and/or errors related to the processing of the data. It is

advisable to periodically generate reports specifying the frequency with which each of the

problems occurs, thus identifying the main sources of error and making the necessary

adjustments in future data collection processes. A brief overview of the recommended data

compilation methods is provided below.62

7.62. Data validation and editing is an essential process for assuring the quality of the

collected data and refers to the systematic examination of data collected from respondents for

identifying and eventually modifying the inadmissible, inconsistent and highly questionable or

62 More information on the different techniques used in data compilation is found, for example, in IRIS 2008.

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improbable values according to predetermined rules. It is important to define validation criteria

that clearly and systematically confirm whether the data satisfy, or not, the requirements of

completeness, integrity, arithmetic consistency and congruence, as well as guarantee their

overall quality. The validation criteria are established by the statistical authority according to

the nature of the data and the analysis of the variables of interest, taking into account

magnitude, structure, trends, relationships, causalities, interdependencies and possible response

ranks.

7.63. In recognizing the importance of the data validation and editing, it should be

emphasized that any arbitrary alteration of the data should not be allowed, and any changes in

the collected data should be based on the relationship between variables and the response

values. To prevent out of range responses and inconsistencies, appropriate response ranges for

each question and the congruence that must exist between responses from related questions

must be established. For example, checking that the sum of available supplies equals the sum

of recorded uses is an important validation criterion. This is also valid for routine

questionnaires directed to the energy industries.

7.64. As validation and editing can be very expensive components of the survey process,

attention should be focused on the most important areas and issues. For example, many survey

responses may have minimal impact on the final results, and effort to correct errors in such

responses may be ineffective. To maximize the effectiveness of the validation and editing

process, the responses that will have the greatest impact on the final results should be identified

prior to the start of the actual process, so that resources can be properly allocated.

7.65. Data imputation. Imputation refers to replacing one or more erroneous responses or

non-responses with plausible and internally consistent values in order to produce a complete

data set. It is used for estimating missing data values when, for example, the respondent has not

answered all relevant questions but only part of them, or when the answers are not logically

correct. There are a variety of imputation methods ranging from simple and intuitive to rather

complicated statistical procedures.

7.66. The choice of methods for imputation depends on the objective of the analysis and the

type of missing data. No method is superior to others in all circumstances.63

In most imputation

systems a mix of imputation methods is used. The following are the desirable properties of all

imputation processes:

(a) The imputed records should closely resemble the missing or failed edit record,

retaining as much respondent data as possible. Thus, the number of imputed data

items should be kept to a minimum;

(b) The imputed records should satisfy all edit checks;

63 For more information on imputation options in the case of item non-response or unit non-response, see IRIS Chapter

VI.B.2.

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(c) The imputed values should be flagged and the used methods and sources of

imputation described in the metadata.

7.67. It is recommended that compilers of energy statistics use imputation as necessary, with

the appropriate methods consistently applied. It is further recommended that these methods

comply with the general requirements as set out in international recommendations for other

domains of economic statistics, such as the International Recommendations for Industrial

Statistics (UN 2009b).

7.68. Grossing up procedures. After the data have been validated and edited and imputations

have corrected for non-response and erroneous responses, special procedures should be applied

to the sample values to estimate the required characteristics of the total population (these are

referred to as “grossing up” procedures). These procedures consist of raising the sample value

with a factor based on the sampling fraction in order to obtain the levels of data for the sample

frame population. In some cases, depending on the relationship with other variables for which

data may exist, more sophisticated statistical techniques can be used for this purpose. As the

application of estimation procedures is a complex undertaking, it is recommended that

specialist expertise always be sought for this task.

7.69. The treatment of outliers is an important estimation consideration, particularly in energy

statistics. Outliers are reported data which are correct but are unusual in the sense that they do

not represent the sampled population and hence may distort the estimates. If the sampling

weight is large and the unadjusted outlier value is included in the sample, the final estimate

will be inappropriately large and unrepresentative as it is driven by one extreme value. The

simplest way to deal with such an outlier is to reduce its weight in the sample so that it

represents itself only. Alternatively, statistical techniques can be used to calculate a more

appropriate weight for the outlier unit. The details on the treatment of outliers should be

provided in the metadata.

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Chapter 8. Energy balances

A. Introduction

8.1. Concept of energy balances. An overall energy balance (referred to as “energy balance” in

the rest of the chapter) is an accounting framework for the compilation and reconciliation of data

on all energy products entering, exiting and used within the national territory of a given country

during a reference period. Such a balance must necessarily express all forms of energy in a

common accounting unit and show the relationship between the inputs to and the outputs from the

energy transformation processes. The energy balance should be as complete as possible so that all

energy flows are, in principle, accounted for. It should be based firmly on the first law of

thermodynamics, which states that the amount of energy within any closed system is fixed and can

neither be increased nor diminished unless energy is brought into or sent out from that system.64

8.2. Balances can also be compiled for any particular energy product (energy commodity) and,

in these cases, are referred to as energy commodity balances or, for brevity, commodity balances.

Commodity balances follow the general structure of energy balances but focus on single energy

products and display some presentational differences. (See Section F of this chapter for details.)

8.3. Purpose of energy balances. An energy balance is a multi-purpose tool to:

(a) Enhance the relevance of energy statistics by providing comprehensive and reconciled

data on the energy situation on a national territory basis;

(b) Provide comprehensive information on the energy supply and demand in the national

territory in order to understand the energy security situation, the effective functioning of

energy markets and other relevant policy goals, as well as to formulate energy policies;

(c) Serve as a quality tool to ensure completeness, consistency and comparability of basic

statistics;

(d) Ensure comparability between different reference periods and between different

countries;

(e) Provide data for the estimation of CO2 emissions with respect to the national territory;

(f) Provide the basis for indicators of each energy product’s role in a country’s economy;

64 It should be noted that the energy balance as presented in this chapter differs from the energy accounts of the SEEA-

Energy, which are developed on the basis of concepts, definitions and classifications of the System of National

Accounts (see Chapter 11 for details).

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(g) Calculate efficiencies of transformation processes occurring in the country (e.g.,

refining, electricity production by combustion of fuels, etc.);

(h) Calculate the relative shares of the supply/consumption of various products (including

renewables versus non-renewables) of a country’s total supply/consumption;

(i) Provide an input for modeling and forecasting.

8.4. The multipurpose nature of the energy balance could be further increased by the

development of supplementary tables that combine information from the balance with additional

information on particular issues that are not explicitly reflected in the balance itself. (See para. 8.50

for further discussion of this issue.)

8.5. Detailed and aggregated energy balances. Energy balances can be presented in both

detailed and aggregated formats. The degree of detail depends on the policy concern, data and

resource availability, and the underlying classifications used. The energy balance in an aggregated

format is usually prepared for dissemination in printed form where the level of aggregation, that is

the number of columns and rows, is mainly constrained by practical considerations. However, it is

recommended that countries collect data at the level of detail that allows for the compilation of a

detailed energy balance, as presented in Table 8.1. When such a level of detail is not available or

practical, it is recommended that countries, at a minimum, follow the template of the aggregated

energy balance presented in Table 8.2.

B. Scope and general principles of energy balance compilation

8.6. The scope of an energy balance is determined, inter alia, by the territory, product and flow

boundaries:

(a) Territory boundary – defined by the boundary of the national territory of the compiling

country (see Chapter 2 for details);

(b) Product boundary – defined by the scope of all energy products shown in the balance

columns (see Chapter 3 for details);

(c) Flow boundary – defined by the scope of energy flows shown in the balance rows (see

Chapter 5 for details).

8.7. The product and flow boundaries are fixed in the short term. However, as technology

advances, new sources of energy may become available and should be reflected in the balances

when used.

8.8. The scope of an energy balance does not include:

(a) Passive energy, such as the heat gain of buildings, solar energy falling on the land to

grow crops, etc.;

(b) Energy resources and reserves (which can nevertheless be considered in additional

tables);

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(c) Extraction of any materials not covered in primary energy production (e.g. natural gas

flared or vented). Data on some such materials are included in the data reference list

(see Chapter 6), and can be shown in an additional table;

(d) Peat, waste and biomass used for non-energy purposes.

8.9. When compiling an energy balance, some general principles on the coverage and structure

of the balance should be taken into account. These principles are as follows:

(a) The energy balance is compiled with respect to a clearly defined reference period. In

this respect, it is recommended that countries, as a minimum, compile and disseminate

an energy balance on an annual basis;

(b) The energy balance is a matrix represented by rows and columns;

(c) Columns represent energy products that are produced and/or are available for use in the

national territory;

(d) The column “Total” contains cells which provide the sum of the data entries in the

corresponding row; however, the meaning of the cells in the “Total” column is not the

same for all rows of the balance;

(e) Rows represent energy flows;

(f) A separate row is reserved for statistical difference, calculated as the numerical

difference between the total supply of an energy product and the total use of it;

(g) The detailed energy balance should contain sufficient rows and columns to show clearly

the relationship between the inputs to and outputs from transformation processes

(production of secondary energy products);

(h) All entries should be expressed in one energy unit (it is recommended that the Joule be

used for this purpose, although countries could use other energy units, such as tons of

oil equivalent, tons of coal equivalent, etc.). The conversion between energy units

should be through the application of appropriate conversion factors (see Chapter 4) and

the applied factors should be reported with the energy balance to make any conversion

from physical units to Joules or other units transparent and comparable;

(i) Net calorific values should be used for measuring the energy content of energy

products. If gross calorific values are used in a country because of the recuperation of

latent heat or for maintenance of historical data series, the corresponding conversion

factors should be reported and countries should clearly identify which method is used;

(j) To give a primary energy equivalent to electricity produced from non-combustible

energy sources, the “physical energy content” method should be used. According to this

method, the normal physical energy value of the primary energy form is used for the

production figure. This is in contrast to the “partial substitution method” which requires

assigning to such electricity a primary energy value equal to the hypothetical amount of

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fuel required to generate an identical amount of electricity in a thermal power station

using combustible fuels. If the partial substitution method is used in a country, that

country should clearly mention this, together with the average generating efficiency of

thermal power stations used to calculate the primary energy equivalent.

In the “physical energy content” method, the normal physical energy value of the

primary energy form is used for the production figure. For primary electricity, this is

simply the gross generation figure for the source. Care is needed when expressing the

percentage contributions from the various sources of national electricity production. As

there is no transformation process recognized within the balances for the production of

primary electricity, the respective percentage contributions from thermal and primary

electricity cannot be calculated using a “fuel input” basis. Instead, the various

contributions should be calculated from the amounts of electricity generated from the

power stations classified by energy source (coal, nuclear, hydro, etc.).

In the case of electricity generation from primary heat (nuclear, geothermal and

concentrating solar), the heat is the primary energy form. As it can be difficult to obtain

measurements of the heat flow to the turbines, it is recommended that an estimate of

the heat input be used based on an efficiency of 33 per cent for nuclear and

concentrating solar, and 10 per cent for geothermal as a default, unless country- or case-

specific information is available. This means that, in the absence of measurements of

the actual heat input, the equivalent primary nuclear or concentrating solar heat is

estimated as three times the electricity produced, and the equivalent geothermal heat is

estimated as ten times the geothermal electricity output.

(k) Production of primary and secondary energy, as well as external trade in energy

products, stock changes, final energy consumption and non-energy use should be

clearly separated to better reflect the structure and relationships between energy flows

and to avoid double-counting.

C. Structure of energy balance: an overview

8.10. Structure. An energy balance is a matrix showing the relationship between energy products

(represented in columns) and flows (represented in rows). The structuring of an energy balance

depends on a country’s energy production and consumption patterns and the level of detail that the

country requires. However, it is recommended that certain common approaches, described below,

be followed to ensure international comparability and consistency.

8.11. Columns. A column refers to a group of energy products. Each cell in this column shows a

flow of energy involving this group of products, as defined by the row name. The number of

columns depends, among other things, on whether the balance is intended for detailed analysis or is

prepared for general dissemination (including printed publications) where space limitations have to

be taken into account. In the first case, the energy balance may contain as many columns as

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needed, while in the second case it should be compact and contain columns that highlight energy

products, especially important for the compiling country, as well as columns needed for

international reporting and comparisons. Even when only a compact version of the energy balance

is compiled and generally disseminated, a more comprehensive electronic version of the energy

balance should be made available to users requiring more detailed information.

8.12. Sequencing of columns. While different columns (except “Total”) represent various energy

products, they might be grouped and sequenced in a way that adds to the analytical value of the

balance. In this connection, it is recommended that:

(a) Groups of energy products be mutually exclusive and based on SIEC;

(b) The column “Total” follow the columns for individual energy products (or groups of

products);

(c) The column “Total” be followed by supplementary columns containing additional

subtotals such as “renewables”. The definition of such subtotals and any additional

clarification on the column’s coverage should be provided in appropriate explanatory

notes.

8.13. Rows. One of the main purposes of an energy balance is to reflect the relationships between

the primary production of energy (and other energy flows entering/exiting the national territory),

its transformation and final consumption. The number of rows and their sequencing in a balance

are intended to make those relationships clear, while keeping the balance compact, especially when

presented in an aggregated format.

8.14. Sequencing of rows. It is recommended that an energy balance contain three main blocks

of rows as follows:

(a) Top block – flows representing energy entering and leaving the national territory, as

well as stock changes to provide information on the supply of energy on the national

territory during the reference period;

(b) Middle block – flows showing how energy is transformed, transferred, used by energy

industries for own use and lost in distribution and transmission;

(c) Bottom block – flows reflecting final energy consumption and non-energy use of energy

products.

8.15. A separate row should be reserved for statistical difference and placed between the top and

middle blocks of the balances.

1. Top block - Energy supply

8.16. The top block of an energy balance – Energy supply – is intended to show flows

representing energy entering the national territory for the first time, energy removed from the

national territory and stock changes. The entering flows consist of the production of primary

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energy products and imports of both primary and secondary energy products. The flows removing

energy from the national territory are exports of primary and secondary energy products and

international bunkers.

8.17. The balance item of the flows described above and the changes in stock represent the

amount of energy that is available in the national territory during the reference period. This

aggregate is named Total energy supply (TES) and calculated as follows:

Total energy supply =

Primary energy production

+ Import of primary and secondary energy

- Export of primary and secondary energy

- International (aviation and marine) bunkers

- Stock changes

8.18. As a common convention, the figures shown in the published energy balances already carry

the sign that would be allocated through the above formula. While this is obvious in the case of

exports and bunkers (e.g., showing an export of “- 1000 tons of coal”), care should be taken when

reading the values for stock changes, as the balances show them with an opposite sign than that

which is described in their definition (see para. 5.16). This results in stock builds being shown with

a negative value, which could be misinterpreted as a stock draw.

8.19. Primary energy production. Primary energy production (as defined in para. 5.10) is the

capture or extraction of fuels or energy from natural energy flows, the biosphere and natural

reserves of fossil fuels within the national territory in a form suitable for use. Inert matter removed

from the extracted fuels and quantities re-injected, flared or vented are not included. The

production of primary products is usually an activity of the energy industries. However, some

primary energy products can be generated by industries other than the energy industries as

autoproduction, as well as by households.

8.20. Imports and exports of energy products. Imports and exports of energy products are defined

in paras. 5.11 and 5.12. They cover both primary and secondary energy products.

8.21. International bunkers. International bunkers cover both marine and aviation bunkers and

are defined in paras. 5.14 and 5.15.

8.22. Stock changes. Stocks and stock changes are defined in para. 5.16. It is desirable, in

principle, to record changes in all stocks located in the national territory at a specific moment in

time but it is recognized that in practice countries often find it difficult to obtain satisfactory data

on changes in stocks held by final energy users. This problem is particularly troublesome in the

case of the numerous non-industrial final users, making it therefore very costly to cover them in

regular stock surveys. As countries may adopt different conventions for the calculation of the

change in energy stocks, it is recommended that necessary clarification be provided in country

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metadata. Countries are encouraged to collect comprehensive data on stock changes from large

companies, private or public, as a minimum.

8.23. A stock change can be the result of a stock build or a stock draw. To ensure comparability

of energy statistics with the accepted practice in other areas of economic statistics, stock changes

are measured as closing stock minus opening stock. Thus, a positive value of stock change is a

stock build and represents a reduction in the supply available for other uses, while a negative value

is a stock draw and represents an addition to the supply for other uses.

8.24. For each product, the row “total energy supply” reflects the supply of energy embodied in

that particular energy product. The total supply of energy in the national territory is shown under

the column “Total”.

2. The middle block

8.25. The main purpose of the middle block of an energy balance is to show transfers, energy

transformation, energy industries own use and losses.

8.26. Transfers, the first line of the middle block, is essentially a statistical device to move

energy between columns to overcome practical classification and presentation issues resulting from

changes in use or identity of an energy product. Transfers cover, for example, the renaming of oil

products (which is necessary when finished oil products are used as feedstock in refineries) and the

renaming of products that no longer meet their original specifications (see para. 5.17).

8.27. Transformation. Energy transformation describes the processes that convert an energy

product into another energy product which, in general, is more suitable for specific uses. (see para.

5.18 and 5.68—5.74)

8.28. The transformation of energy is normally performed by energy industries. However, many

economic units not part of energy industries produce energy products to satisfy their own needs

and/or to sell to third parties. When this involves the transformation of energy products, it is

recorded in the balances in the middle block. Examples include manufacturing plants producing

their own secondary electricity or heat (autoproducers). Another example of an economic unit

included in transformation is blast furnaces (ISIC Group: 241 – Manufacture of basic iron and

steel), because its by-product, blast furnace gas, can have different energy uses, making it

worthwhile to account for as the output of the transformation of coke.

8.29. Number of rows describing transformation. Each row under transformation specifies the

kind of plant performing the energy transformation. A reference list of transformation plants and,

therefore, rows to be reflected in the transformation part of the balance is provided in para. 5.70. It

is recommended that countries show in their balances, to the extent possible and applicable,

energy transformation by the categories of plants, as presented in para. 5.70.

8.30. Recording of inputs and outputs. It is recommended that: (a) energy entering

transformation processes (e.g., fuels into electricity generation and heat generation, crude oil into

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oil refineries for the production of oil products, or coal into coke ovens for the production of coke

and coke oven gas) be shown with a negative sign to represent the input and (b) energy that is an

output of transformation activities be shown as a positive number. The sum of the cells in each row

appearing in the column “Total” should therefore be negative as transformation always results in a

certain loss of energy when expressed in energy units. A positive figure would suggest a gain of

energy and, as such, would be an indication of incorrect data or metadata such as conversion

factors.

8.31. Energy industries own use is defined as the consumption of fuels, electricity and heat for

the direct support of the production and preparation for use of fuels and energy, except heat not

sold (see para. 5.20). As such, it covers not only own use by the energy industries as defined in

para. 5.23, but also by other energy producers as defined in para. 5.75. Typical examples are the

consumption of electricity in power plants for lighting, compressors and cooling systems, or the

fuels used to maintain the refinery process. A separate row in commodity and energy balances is

used to show this consumption of energy for the purposes of energy production. For analytical

purposes, the energy industries own use will often be further disaggregated by type of energy

industry.

8.32. Losses. As defined in para. 5.19, losses are those that occur during the transmission,

distribution and transport of fuels, electricity and heat. Losses also include venting and flaring of

manufactured gases, losses of geothermal heat after production and pilferage of fuels or electricity

(sometimes referred to as non-technical losses).

3. The bottom block - Final consumption

8.33. The bottom block of an energy balance - final consumption - covers final energy

consumption (i.e. flows reflecting energy consumption by energy consumers), as well as non-

energy use of energy products. The final consumption is measured by the deliveries of energy

products to all consumers. It excludes deliveries of fuel and other energy products for use in

transformation processes and the use of energy products for the energy needs of the energy

industries (both covered in the middle block).

8.34. As the energy balance involves application of the territory principle, final consumption

covers all consumption in the national territory independent of the residence status of the

consuming units. Thus, the energy consumption by residents abroad is excluded, while the energy

consumed by non-residents (foreigners) within the national territory is included.

8.35. It is recommended that final energy consumption be grouped into three main categories:

(i) manufacturing, construction and non-fuel mining industries, (ii) transport and (iii) other, and

further disaggregated according to countries’ needs (see Chapter 5 for more detail).

8.36. Manufacturing, construction and non-fuel mining industries. The final consumption

recorded under this category covers the use of energy products for energy purposes by economic

units belonging to the industry groups listed below. It, however, excludes the use of energy

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products for transport, which is recorded under Transport in a separate row. Taking into account

the needs of energy policy makers and to ensure cross country comparability of energy balances, it

is recommended that, in their energy balance, countries show final energy consumption

disaggregated according to the following groups (see Table 5.3):65

• Iron and steel

• Chemical and petrochemical

• Non-ferrous metals

• Non-metallic minerals

• Transport equipment

• Machinery

• Mining and quarrying

• Food and tobacco

• Paper, pulp and print

• Wood and wood products (Other than pulp and paper)

• Textile and leather

• Construction

• Industries, not elsewhere specified

8.37. Transport. The purpose of this category is to provide information on the consumption of

energy products by any economic entity in transporting goods and/or passenger between points of

departure and destination within the national territory. As described in para. 5.89—5.96, transport

should be disaggregated by mode of transport.

8.38. By convention, transport fuels used in fishing, farming and defence (including fuels for

military means of transport) are not part of transport in the energy balance, because the main

purpose of the fuel use in these activities is not for transport but rather for agriculture and defence.

Similarly, energy used in lift trucks and construction machinery on industrial sites is considered as

stationary consumption, not transport. The category “transport” is subdivided into the following

modes of transport (see Table 5.4):

• Road

• Rail

• Domestic aviation

65 In addition, to ensure better harmonization of energy statistics with other economic statistics countries might also

wish to compile energy consumption by applicable ISIC Rev.4 classes in their detailed energy balances.

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• Domestic navigation

• Pipeline transport

• Transport not elsewhere specified

8.39. Energy used at compressor and/or pumping stations in pipeline transport (fuels and

electricity) within the national territory is included in transport. However, it is recognized that

some countries with a large production of oil and gas find it difficult to differentiate between

energy for pipeline transport and other fuels consumed in the oil and gas extraction industries.

8.40. Other. This group consists of energy consumers not classified in the manufacturing,

construction and non-fuel mining industries category. It is recommended that countries at least

subdivide this group in the following way (see Chapter 5).

• Households

• Commerce and public services

• Agriculture, Forestry

• Fishing

• Not elsewhere specified (including defence activities)

8.41. As stated in para. 8.38 above, fuels used in tractors for the purpose of farming, in vessels

for fishing and for transport by military vehicles are included here. Fuels and other energy

products’ consumption in fishing should cover all fishing vessels, including those engaged in deep-

sea fishing. It is important to ensure that fuels and other energy products delivered to deep-sea

fishing vessels are excluded from quantities reported as international marine bunkers.

8.42. It is recommended that countries further subdivide the major consumer groups identified

above, reflecting their needs and the level of detail adopted in other areas of basic statistics.

8.43. Use of energy products for non-energy purposes. This use appears as a separate row in the

energy balance. It can be further disaggregated by the compiling countries in accordance with their

needs and priorities. For example, countries may wish to show non-energy use of energy products

by the chemical and petrochemical industry, for transport66

and others.

8.44. The structure of the middle and bottom blocks of energy balances is designed to present

various uses of energy products based on the concepts introduced in Chapter 5. Figure 8.1 below

illustrates how the cross-classification of energy use by purpose and user groups described in

Chapter 5 and presented in Figure 5.2 is reflected in energy balances.

66 In some balances, there is a separate item for transport. One example of non-energy use in transport is lubricants and

greases used in engines.

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Figure 8.1: Uses of energy and their presentation in an energy balance

4. Statistical difference

8.45. In the energy balance, the statistical difference is the numerical difference between the total

supply of an energy product and the total use of it. It is presented in line “2” of the energy balance,

as displayed in Tables 8.1 and 8.2, and is calculated by subtracting the total use of energy (sum of

lines 3 to 7) from the total supply of energy products (line 1). It arises from various practical

limitations and problems related to the collection of the data which make up supply and demand.

For example, the data may be subject to sampling or other collection errors, and/or be taken from

different data sources that use different time periods, different spatial coverage, different fuel

specifications or different conversions from volume to mass or from mass to energy content in the

supply and demand sides of the balance. The reasons for a large statistical difference should be

examined because this indicates that the input data are inaccurate and/or incomplete.

8.46. Statistical differences in commodity balances can provide an explanation for large

statistical differences in an energy balance. For example, if the commodity balances show

negligible statistical differences, this may indicate that the conversion factors to energy units

should be investigated, as they may be the reason for the large statistical difference in the energy

balance. Alternatively, if the statistical difference for a specific product’s commodity balance is

large, this may indicate that efforts should be made to investigate the data collection for that

specific product. It is acknowledged that countries’ experiences do vary with respect to the

presentation and treatment of statistical differences. The forthcoming Energy Statistics Compilers

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Manual (ESCM) will provide an overview of the issues involved and identify good practices that

countries might wish to follow.

D. Templates of detailed and aggregated energy balances

8.47. As mentioned above, it is recommended that countries compile and disseminate an official

annual energy balance every year. It is further recommended that countries follow as much as

possible the template of a detailed energy balance as presented in Table 8.1 below.

Table 8.1: Template of a detailed energy balance

Item code Flows Energy products

E1 E2 E3 … Total of which:

Renewables

1.1 Primary production

1.2 Imports

1.3 Exports

1.4.1 International Marine Bunkers

1.4.2 International Aviation Bunkers

1.5 Stock changes (closing-opening stocks)

1 Total energy supply

2 Statistical difference

3 Transfers

4 Transformation processes

4.1 Electricity plants

4.2 CHP plants

4.3 Heat plants

4.3 Coke ovens

4.4 Patent fuel plants

4.5 Brown coal briquette plants

4.6 Coal liquefaction plants

4.7 Gas works (and other conversion to gases)

4.8 Blast furnaces

4.9 Peat briquette plants

4.10 Natural gas blending plants

4.11 Gas-to-liquids (GTL) plants

4.12 Oil refineries

4.13 Petrochemical plants

4.14 Charcoal plants

4.15 Other transformation processes

5 Energy Industries own use

6 Losses

7 Final consumption

7.1

Final energy consumption

7.1.1 Manufacturing, const. and non-fuel mining industries, Total

7.1.1.1 Iron and steel

7.1.1.2 Chemical and petrochemical

7.1.1.3 Non-ferrous metals

7.1.1.4 Non-metallic minerals

7.1.1.5 Transport equipment

7.1.1.6 Machinery

7.1.1.7 Mining and quarrying

7.1.1.8 Food and tobacco

7.1.1.9 Paper, pulp and print

7.1.1.10 Wood and wood products (Other than pulp and paper)

7.1.1.11 Textile and leather

7.1.1.12 Construction

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7.1.1.13 Industries not elsewhere specified

7.1.2 Transport, Total

7.1.2.1 Road

7.1.2.2 Rail

7.1.2.3 Domestic aviation

7.1.2.4 Domestic navigation

7.1.2.5 Pipeline transport

7.1.2.6 Transport not elsewhere specified

7.1.3 Other, Total

7.1.3.1 Agriculture and Forestry

7.1.3.2 Fishing

7.1.3.3 Commerce and public services

7.1.3.4 Households

7.1.3.5 Not elsewhere specified

7.2 Non energy use

8.48. It is recognized that countries may compile balances using a different format/structure. In

some cases, an aggregated format may be sufficient and countries may adopt the aggregations that

best suit their national purposes. However, to ensure international comparability and assist in

monitoring implementation of various international agreements and conventions, it is

recommended that the template presented in Table 8.2 be used, as applicable, when only main

aggregates have to be shown.

Table 8.2: Template of an aggregated energy balance

Item code Flows Energy products

E1 E2 E3 … Total of which:

Renewables

1.1 Primary production

1.2 Imports

1.3 Exports

1.4 International Bunkers

1.5 Stock change (closing-opening)

1 Total energy supply

2 Statistical difference

3 Transfers

4 Transformation processes

5 Energy Industries own use

6 Losses

7 Final consumption

7.1 Final energy consumption

7.1.1 Manufacturing, const. and non-fuel mining industries, Total

7.1.1.1 Iron and steel

7.1.1.2 Chemical and petrochemical

7.1.1.X Other Industries

7.1.2 Transport, total

7.1.2.1 Road

7.1.2.2 Rail

7.1.2.3 Domestic aviation

7.1.2.4 Domestic navigation

7.1.2.X Other Transport

7.1.3 Other, total

7.1.3.1 Of which: Agriculture, forestry and fishing

7.1.3.2 Of which: Households

7.2 Non energy use

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8.49. Additional information can be presented in supplementary tables and/or memorandum

items to the energy balances. Examples of such information are: (i) flaring, venting and re-injection

which might occur during the primary energy production, but are not covered in the balances (data

item 3.3 Extraction losses in Chapter 5); and (ii) flaring, venting and re-injection which occur

during the transformation processes and even though covered in the energy balances they are not

explicitly identified (included under Losses). The collection and compilation of such information

are very useful for a number of reasons, including their relevance for greenhouse gas emissions

and, in the case of the extraction losses, their links with the assessment of the depletion of

underground deposits of the resource. In order to respond to specific user needs, supplementary

information could be presented together with the energy balance.

E. Data reconciliation and estimation of missing data

8.50. It is recognized that the compilation of an energy balance will require the use of various

sources of data, including those collected by energy statisticians, as well as by compilers working

in other statistical domains. This implies that the assessment of data accuracy, data reconciliation,

estimation of missing data and imputation will play a significant role in processing the data during

the compilation of the energy balance. While detailed information on good practices will be

provided in the ESCM, some general recommendations can be formulated and are presented

below.

Accuracy requirements

8.51. An energy balance includes interdependent elements of significantly differing levels of

reliability and it may become very difficult to assess the accuracy of the aggregated data. Such

difficulties should not, however, be regarded as insurmountable barriers to progress but as

challenges to be addressed as experience is gained and good practices are identified. It is

recommended that accuracy requirements applicable to basic energy data used in the balance be

clearly described in the energy statistics metadata of the country.

Estimation of missing data

8.52. It is recommended that countries estimate missing data in order to maintain the integrity of

the balance and follow the imputation methods and general principles established in other areas of

statistics,67

as well as good practices applicable to energy statistics, which will be elaborated in the

forthcoming ESCM. (See also Chapter 7 for a discussion of editing and imputation.)

67 See, for example, International Recommendation for Industrial Statistics (IRIS) 2008.

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Reconciliation

8.53. As the compilation of energy balances requires use of data obtained from various data

sources, reconciliation is needed to ensure the coherence of the data and the absence of double

counting. It is recommended that countries provide a summary of the performed reconciliation in

the energy balance metadata to ensure the transparency of the energy balance preparation and to

assist users in proper interpretation of the information contained therein and its relationship with

other disseminated statistics.

8.54. Reconciliation of data on imports and exports of energy products and international

bunkers. Examples of data that need special attention are data on imports/exports of energy

products and international bunkers. As official foreign merchandise trade statistics do not always

satisfy the needs of balance compilers in this case, enterprise surveys might be needed to

complement it in order to distinguish between these flows. However, it is recommended that the

suitability of foreign merchandise trade statistics always be reviewed and available data used to the

maximum extent possible to avoid duplication of efforts and publication of contradictory figures.

If, however, the use of enterprise surveys becomes necessary and differing figures on exports and

imports of energy products are to be published in energy balances and trade statistics, an

appropriate explanation of the differences should be published as part of the energy balance

metadata. It is further recommended that energy and trade statisticians regularly review data

collection procedures to ensure that the needs of energy statistics are met to the extent possible. A

national correspondence table between the Harmonized Commodity Description and Coding

System (HS) and SIEC should be developed and used to present external trade flows in the energy

categories adopted for energy balance purposes.

F. Commodity balances

8.55. Purpose. The purpose of a commodity balance is to show the sources of supply and the

various uses of a particular energy product with reference to the national territory of the compiling

country. The balance can be compiled for any energy commodity. Countries may use various

formats of commodity balances depending on their needs and circumstances. However, it is

recommended that the format of the energy balance and all applicable concepts defined in IRES

be consistently used in the compilation of a commodity balance to ensure data consistency.

8.56. The unit of measurement. The unit of measurement used in commodity balances is usually

the original unit appropriate for the energy product in question (e.g., metric tons). However, a non-

original energy unit (e.g., ton of oil equivalent (TOE) or Terajoule) can be used as well.

8.57. Format (template) of commodity balance. In general, a commodity balance can be compiled

in a format similar to that of energy balances. However, not all flows (i.e. rows in the balance) may

be applicable for all products. Common flows shown are:68

68 For definitions and relationships between these terms refer to Chapter 6.

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• Production (primary or secondary)

• Production from other sources

• Imports

• Exports

• International bunkers

• Stock changes

• Supply

• Statistical difference

• Transfers

• Transformation input

• Energy industries own use

• Losses

• Final consumption

• Final energy consumption

• Non-energy use

8.58. The most commonly used format for the presentation of energy commodity data is the

commodity balance in which both the sources of supply and the uses for each commodity are

shown in a single column.

8.59. It is recommended that commodity balances be constructed at the national level for every

energy commodity in use, however minor, with certain commodities aggregated for working

purposes. They should be considered as the basic framework for the compilation of national energy

statistics and as a valuable accounting tool for constructing both energy balances and higher

aggregates. A key indicator of the data quality of each product is the statistical difference row (see

para. 8.45).

8.60. Differences in the flow layout of commodity balances as compared to an energy balance.

Commodity balances provide details on the physical flows involving one energy product, and do

not consider the interrelationships between different products. For this reason, it is logical to treat

secondary production as “production” (in line with the concept of production in other areas of

statistics) and not as the “output of transformation”, while at the same time there is no need to

show transformation inputs as a negative quantity.

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8.61. While energy balances need to distinguish between fossil and non-fossil fuels, both to show

what is renewable in total and to accurately calculate greenhouse gas inventories, for commodity

balances, however, more interest lies in quantities consumed and the way they are. For example,

commodity balances showing consumption of motor gasoline will include any quantities of

blended biofuels, in contrast to energy balances.

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Chapter 9. Data Quality Assurance and Metadata

A. Introduction

9.1. Ensuring data quality is a core challenge of all statistical offices and other data-

producing agencies. The management of data quality is an integral part of every statistical

domain or programme, and has to be addressed in each of them. Energy data made available to

users, like other subject-matter area statistics, are the end product of a complex process

comprising many stages. These include the definition of concepts and variables (such as energy

products and flows), the collection of data from various sources, the processing, analysis and

formatting of the data to meet user needs, and data dissemination, which should be followed by

an evaluation of the process and outputs to confirm that the objectives have been met and to

suggest possible improvement actions. Achieving overall data quality is dependent upon

ensuring quality in all stages of this process.

9.2. This chapter discusses quality concepts and quality frameworks, defines and describes

the different dimensions of statistical quality and trade-offs among them, and discusses quality

measures and indicators for measuring quality. Quality reports are described next, followed by

a summary of the types of quality reviews that can be undertaken to evaluate statistical

programmes. The chapter ends with a discussion of metadata.

B. Data quality, quality assurance and quality assurance frameworks

1. Data quality

9.3. For sound decision-making and policy formulation in the energy domain, it is essential

that high quality statistical information about the supply and use of energy be available. While

the word “quality” can have different meanings depending on the context in which it is used,

data quality is most commonly defined in terms of its “fitness for use”, or how well the

statistical outputs meet user needs. The definition is thus a relative one that allows for various

perspectives on what constitutes quality, depending on the purposes for which the outputs are

intended.

2. Quality assurance

9.4. Quality assurance comprises all planned and systematic activities that can be

demonstrated to provide confidence that the statistical products or services are adequate or fit

for their intended uses by clients and stakeholders. It entails anticipating and avoiding

problems, with the goal of preventing, reducing or limiting the occurrence of errors (e.g. in a

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survey). It is worth noting here that quality assessment is a part of quality assurance that

focuses on assessing or determining the extent to which quality requirements have been

fulfilled.

9.5. Activities or measures for ensuring that attention is paid to the quality of the data cover

not only the final outputs, but also the organization producing the outputs and the underlying

processes that lead to the outputs. The outputs or products are typically described in terms of

quality dimensions such as relevance, accuracy, reliability, timeliness, punctuality,

accessibility, clarity, coherence, and comparability. The organization or agency exhibits high

quality when it maintains a professionally independent, impartial and objective institutional

environment, a commitment to quality, the guarantee of confidentiality and transparency, and

provides adequate resources for producing the outputs. For those processes that the

organization considers to be high priority, the use of sound statistical methodologies and cost-

effective procedures that minimize the reporting burden must be paramount.

9.6. To achieve this, quality is approached along three lines: statistical product (or output)

quality; process quality; and the quality or characteristics of the environment in which the

office/agency operates. The focus in this chapter will be on ensuring statistical product (or

output) quality.

3. Data quality assurance frameworks

9.7. In the context of a statistical office, systematic data quality management typically takes

the form of a quality assurance framework. A national quality assurance framework can be

viewed as an overarching framework that can provide context for a country’s quality concerns,

activities and initiatives, and explain the relationships between the various quality procedures

and tools. Quality assurance frameworks have been developed and adopted to date by countries

and international organizations to varying degrees. While all countries’ statistical offices have

in place some type of quality assurance approach and a number of quality assurance

procedures, and most have similar outlines of the various dimensions of quality (also referred

to in the quality assurance literature as criteria, components or aspects), not all countries yet

have a formalized quality assurance framework in place.

9.8. In 2012, the United Nations Statistical Commission endorsed the generic National

Quality Assurance Framework (NQAF) Template, developed by the Expert Group on National

Quality Assurance Frameworks to assist countries in formulating and operationalizing their

national quality assurance frameworks or to further enhance existing ones. The work of the

Expert Group built upon and helped raise greater awareness of the various data quality

management references and tools developed by international, regional, national and other

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organizations. They are posted on the United Nations Statistics Division (UNSD) NQAF

website.69

9.9. The NQAF Template drew heavily upon, and was designed to be in close alignment

with other main frameworks, i.e., the European Statistics Code of Practice, the International

Monetary Fund (IMF) Data Quality Assessment Framework (DQAF), Statistics Canada Quality

Assurance Framework, and the Code of Good Statistical Practice for Latin America and the

Caribbean,70

which have been successfully adopted by many countries and continue to be in

use in them. Although these quality frameworks may differ slightly from each other, they share

common aspects and provide comprehensive and flexible structures for the qualitative

assessment of a broad range of statistics, including energy statistics. They also facilitate taking

stock of quality concerns, activities, requirements and initiatives and the fostering of

standardization and systematization of quality practices and measurement within statistical

offices and across countries. A mapping of each of them to the NQAF Template is available on

the UNSD NQAF website.

9.10. The NQAF Template is presented in Box 9.1 below. Its five sections outline the

elements that a national quality assurance framework should include. The paragraphs on

quality assurance that follow focus mainly on the NQAF Template, sections 3 and 4, and

provide an overview of quality assurance objectives, considerations and practices, including

measurement, reporting and evaluation. Additional information on other frameworks can be

found in the Energy Statistics Compilers Manual.

Box 9.1: Template for a Generic National Quality Assurance Framework

Template for a Generic National Quality Assurance Framework (NQAF)

1. Quality context 3d. Managing statistical outputs 1a. Circumstances and key issues driving the need [NQAF14] Assuring relevance for quality management [NQAF15] Assuring accuracy and reliability 1b. Benefits and challenges [NQAF16] Assuring timeliness and punctuality

1c. Relationship to other statistical agency policies, [NQAF17] Assuring accessibility and clarity

strategies and frameworks and evolution over time [NQAF18] Assuring coherence and comparability [NQAF19] Managing metadata 2. Quality concepts and frameworks 2a. Concepts and terminology 4. Quality assessment and reporting 2b. Mapping to existing frameworks 4a. Measuring product and process quality -- use of quality

indicators, quality targets and process variables and descriptions

69 See http://unstats.un.org/unsd/dnss/QualityNQAF/nqaf.aspx.

70 The NQAF Template is available at http://unstats.un.org/unsd/dnss/QualityNQAF/nqaf.aspx, the ES Code of

Practice at http://ec.europa.eu/eurostat/documents/3859598/5921861/KS-32-11-955-EN.PDF/5fa1ebc6-90bb-43fa-

888f-dde032471e15 and http://ec.europa.eu/eurostat/documents/3859598/5923349/QAF_2012-EN.PDF/fcdf3c44-

8ab8-41b8-9fd0-91bd1299e3ef?version=1.0; IMF’s DQAF at

http://dsbb.imf.org/images/pdfs/dqrs_Genframework.pdf; the LAC’s Code of Good Practice in Statistics at

http://www.dane.gov.co/files/noticias/BuenasPracticas_en.pdf; and Statistics Canada’s Quality Assurance Framework

at http://www.statcan.gc.ca/pub/12-586-x/12-586-x2002001-eng.pdf.

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3. Quality assurance guidelines 4b. Communicating about quality – quality reports 3a. Managing the statistical system 4c. Obtaining feedback from users [NQAF 1] Coordinating the national statistical system 4d. Conducting assessments; labelling and certification [NQAF 2] Managing relationships with data users and 4e. Assuring continuous quality improvement data providers [NQAF 3] Managing statistical standards 5. Quality and other management frameworks 5a. Performance management 3b. Managing the institutional environment 5b. Resource management [NQAF 4] Assuring professional independence 5c. Ethical standards [NQAF 5] Assuring impartiality and objectivity 5d. Continuous improvement [NQAF 6] Assuring transparency 5e. Governance [NQAF 7] Assuring statistical confidentiality and security [NQAF 8] Assuring the quality commitment [NQAF 9] Assuring adequacy of resources 3c. Managing statistical processes [NQAF 10] Assuring methodological soundness [NQAF 11] Assuring cost-effectiveness [NQAF 12] Assuring soundness of implementation [NQAF 13] Managing the respondent burden

4. Objectives, uses and benefits of quality assurance frameworks

9.11. The overall objective of quality assurance frameworks is to standardize and systematize

quality practices and measurement within statistical offices and across countries. They are

useful as organizing frameworks that provide a single place to record and reference the full

range of current quality concepts, policies and practices, and for being forward looking, since

they take into account future actions and activities. For energy statistics programmes, the

framework can allow the assessment of national practices in energy statistics in terms of

internationally (or regionally) accepted approaches for data quality management and

measurement and facilitate reviews of a country’s energy statistics programme as performed by

international organizations and other groups of data users.

9.12. The main benefits of having a quality assurance framework in place are that it: (a)

makes the processes by which quality is assured more transparent and reinforces the image of

the office as a credible provider of good quality statistics; (b) creates a quality culture within

the organization; (c) guides countries in strengthening their statistical systems by promoting

self-assessments to identify quality problems; and (d) facilitates the exchange of ideas on

quality management with other producers of statistics at the national, regional and international

levels.

9.13. For those energy statistics programmes without a quality assurance framework yet in

place, national statistical offices, ministries and/or agencies responsible for energy statistics

can avoid “reinventing the wheel” by reviewing the above-mentioned frameworks and

considering whether to directly follow one or structure their own in line with one or some of

them in a way that best fits their country’s practices and circumstances. Countries are

encouraged to develop their own national quality assurance frameworks based on the above-

mentioned approaches or other internationally recognized approaches, taking into consideration

their specific national circumstances.

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5. Dimensions of quality

9.14. It is widely recognized that the concept of quality in relation to statistical information is

multidimensional; there is no one single measure of data quality and no longer is accuracy

thought to be the one absolute measure or indicator of high quality data. Data outputs are

typically described in the various quality assurance frameworks in terms of several dimensions

or components of quality. The dimensions are assessed, measured, reported on and monitored

over time to provide an indication of output quality to both the data users and data producers.

The following dimensions of quality reflect a broad perspective and have been incorporated in

most of the existing frameworks: relevance, accuracy, reliability, timeliness, punctuality,

accessibility, clarity, coherence, and comparability.71

As the dimensions of quality are

overlapping and interrelated, the adequacy of the management of each of them is essential if

the information produced is to be fit for use. They should be taken into account when

describing, measuring and reporting the quality of statistics in general and energy statistics in

particular.

(a) Relevance. The relevance of statistical information reflects the degree to which the

information meets or satisfies the current and/or emerging needs of key users.

Relevance therefore refers to whether the required statistics are produced and whether

those produced are in fact needed and shed light on the issues of most importance to

users. To know this requires the identification of user groups and knowledge about their

various data needs and expectations. Relevance also covers methodological soundness,

particularly the extent to which the concepts, definitions and classifications correspond

to those that users require. Relevance can be seen as having the following three

components: completeness, user needs, and user satisfaction.

An energy statistics programme’s challenge would be to weight and balance the

conflicting needs of its current and potential users in order to produce energy statistics

that satisfy the most important needs of the key users in terms of the data’s content,

coverage, timeliness, etc., within given resource constraints. To ensure or manage

relevance, producers must engage with their users and data providers before and during

the production process, as well as after the outputs have been released. Some strategies

for measuring the relevance of an energy programme’s outputs include consulting

directly with key users about their needs, priorities and views concerning any

deficiencies in the programme, tracking requests from users and evaluating the ability

of the programme to respond, and analysing the results of user satisfaction surveys.

Also, since needs evolve over time, ongoing statistical programmes should be regularly

reviewed to ensure their continued relevance.

71 Some frameworks also include other dimensions, for example, interpretability (which is similar to clarity),

credibility, integrity, serviceability, etc.

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(b) Accuracy and reliability. The accuracy of statistical information reflects the degree

to which the information correctly estimates or describes the phenomena it was

designed to measure, i.e. the degree of closeness of estimates to true values. It has many

facets and there is no single overall measure of accuracy. It is usually characterized in

terms of the errors in statistical estimates and is traditionally decomposed into bias

(systematic error) and variance (random error) components. In the case of energy

estimates based on data from sample surveys, the accuracy can be measured using the

following indicators: coverage rates, sampling errors, non-response errors, response

errors, processing errors, and measurement and model assumption errors.

Reliability is an aspect of accuracy. It concerns whether the statistics consistently

measure over time the reality they are designed to represent. The regular monitoring of

the nature and extent of revisions to energy statistics is considered a gauge of reliability.

(c) Timeliness and punctuality. Timeliness of information refers to the length of time

between the end of the reference period to which the information relates and its

availability to users. Timeliness targets are derived from considerations of relevance, in

particular the period for which the information remains useful for its main purposes.

This varies with the rate of change of the phenomena being measured, the frequency of

measurement, and the immediacy of user response to the latest data. Planned timeliness

is a design decision, often based on a trade-off between accuracy and cost. Thus,

improved timeliness is not an unconditional objective. However, timeliness is an

important characteristic that should be monitored over time to provide a warning of

deterioration, especially as the timeliness expectations of users are likely to heighten as

they continue to experience faster and faster service delivery, thanks to the impact of

technology. Punctuality refers to whether data are delivered on the dates promised,

advertised or announced (for example, in an official release calendar).

Mechanisms for managing timeliness and punctuality include announcing release dates

well in advance, implementing follow-up procedures with data providers if they have

not responded by the specified deadlines, releasing preliminary data followed by revised

and/or final figures, making the best use of modern technology and adhering to the pre-

announced release schedules (and if necessary, informing users of any divergences from

the advance release calendar and the reasons for the delays). Paying attention to

timeliness and punctuality and announcing schedules and release dates in advance help

users plan, provide internal discipline and guarantee equal access to all by undermining

any potential effort by interested parties to influence or delay any particular release for

their own benefit.

(d) Coherence and comparability. The coherence of energy statistics reflects the degree

to which the data are logically connected and mutually consistent, that is to say, the

degree to which they can be successfully brought together with other statistical

information within a broad analytic framework and over time. Comparability is a

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measurement of the impact of differences in applied statistical concepts, measurement

tools and procedures, when statistics are compared between geographical areas or over

time. The use of standard concepts, definitions, classifications and target populations

promotes coherence and comparability, as does the use of a common methodology

across surveys. The coherence and comparability concepts can be broken down into

coherence within a dataset (internal coherence, e.g. checking across products in an

energy balance), coherence across datasets (e.g. checking that concepts such as

production and trade agree with economic and customs statistics, respectively), and

comparability over time and across countries.

Mechanisms for managing the coherence and comparability of energy statistics include

adherence to the methodological basis of the recommendations presented in IRES when

data items are compiled, and the promotion of cooperation and exchange of knowledge

between individual statistical programmes. Automated processes and methods, such as

coding tools, can be used to identify issues and promote coherence and consistency

within a dataset. The use of common concepts, definitions, classifications and

methodology will result in coherence across datasets (e.g. between energy and other

statistics such as economic and environmental), and comparability over time and across

countries. Divergences from the recommendations and common concepts, definitions,

classifications and methodology, as well as breaks in series resulting from changes in

the concepts, definitions, etc. should be explained.

(e) Accessibility and clarity. Accessibility of information refers to the ease with which

users can learn of its existence, locate it, and import it into their own working

environment. It includes the suitability of the form or medium through which the

information can be accessed and its cost. An advance release calendar or timetable to

inform users about when and where the data will be available and how to access them

promotes accessibility and also enables equal access to information for all groups of

users. A provision for allowing access to microdata for research purposes, in accordance

with an established policy which ensures statistical confidentiality, also promotes

accessibility.

Clarity refers to the extent to which easily comprehensible metadata are available in

cases where the metadata are necessary to give a full understanding of the statistics. It is

sometimes referred to as “interpretability”. The clarity dimension is fulfilled by the

existence of user support services and the provision of metadata, which should cover the

underlying concepts and definitions, origins of the data, the variables and classifications

used, the methodology of data collection and processing, and indications of the quality

of the statistical information. User feedback is the best way to assess the clarity of data

from the user’s perspective, e.g. through questions regarding their understanding and

interpretation in user satisfaction surveys.

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6. Interconnectedness and trade-offs

9.15. The dimensions of quality described above are interconnected and as such are involved

in a complex relationship. Action taken to address or modify one dimension of quality may

affect other dimensions. The accuracy-timeliness trade-off is probably the most frequently

occurring and most important of the trade-offs. For example, striving for improvements in

timeliness by reducing collection and processing time may reduce accuracy. A similar situation

requiring consideration by energy statistics programmes, for example, would be the trade-off

between aiming for the most accurate estimation of the total annual energy production or

consumption by all potential producers and consumers, and providing this information in a

timely manner when it is still of interest to users. It is recommended that if, while compiling a

particular energy statistics dataset, countries are not in a position to meet the accuracy and

timeliness requirements simultaneously, they produce provisional estimates, which would be

available soon after the end of the reference period but would be based on less comprehensive

data content. These estimates would be supplemented at a later date with information based on

more comprehensive data content but would be less timely than their provisional version. In

such cases, the tracking of the size and direction of revisions can serve to assess the

appropriateness of the chosen timeliness-accuracy trade-off. Additional trade-offs, such as

those between relevance and comparability over time, may need to be dealt with when changes

made in classifications used in ongoing surveys to improve relevance lead to reductions in

comparability over time due to breaks in series.

9.16. Other trade-offs. The trade-offs described above relate to those between two dimensions

of output quality. Other conflicting situations may emerge requiring difficult trade-offs, such as

those between one of the dimensions and such quality considerations as the respondent burden,

confidentiality, transparency, security or costs. For example, ensuring the efficiency or cost-

effectiveness of the statistical programme may create challenges for ensuring relevance by

limiting the flexibility of the programme to address important gaps and deficiencies. A careful

examination of all relevant factors and priorities will be required to make the necessary

decisions relating to these types of difficult trade-offs, and those decisions already made should

be communicated to users, along with the reasons for making those decisions.

C. Measuring and reporting on the quality of statistical outputs

1. Quality measures and indicators

9.17. There are essentially two ways to measure quality—using quality measures and quality

indicators. The quantitative and qualitative quality measures and indicators developed around

dimensions, such as those described above, enable data producers to describe, measure, assess

and report output quality to assist users in determining whether the outputs are fit for the

intended purposes. The measures and indicators can also be used by data producers to monitor

data quality for the purpose of continuous improvement.

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9.18. Quality measures are defined as those items that directly measure a particular aspect of

quality. For example, the time lag from the reference date to the day of publication of particular

energy statistics, measured in the number of days, weeks or months, is a direct quality measure

of timeliness. In practice, many other quality measures can be difficult and costly to calculate.

In these cases, quality indicators can be used to supplement or act as substitutes for the desired

quality measures.

9.19. Quality indicators usually consist of information that is a by-product of the statistical

process. They do not measure quality directly but can provide enough information to give an

insight into quality. For example, in the case of accuracy, measuring non-response bias is

challenging since the characteristics of the non-responders can be difficult and costly to

ascertain. In this instance, response rates are often utilized as a proxy to provide a quality

indicator of the possible extent of non-response bias. Other data sources can also serve as a

quality indicator to validate or confront the data. For example, commodity balances can be

used to compare energy consumption data with energy supply figures (in the statistical

difference flow) to flag potential problem areas.

2. Examples and selection of quality measures and indicators

9.20. There are numerous examples of quality indicators and measures that have already been

defined around specific dimensions and are in use by statistical organizations. Some are

presented in the form of descriptive statements or assertions (e.g. the majority of the indicators

of good practice relating to the principles of the European Statistics Code of Practice; the

“elements to be assured” in the NQAF Guidelines and NQAF Checklist, and those relating to

the International Monetary Fund (IMF) “elements of good practice” in the DQAF and the

“compliance criteria” in the Code of Good Statistical Practice for Latin America and the

Caribbean). Others may be quantitative statements or quantified measures calculated according

to specific formulas (e.g. the ESS Standard Quality and Performance Indicators). The various

quality indicators and measures are intended to make the description of a product by quality

dimensions more informative and increase transparency. Countries are encouraged to develop

or identify a set of quality measures and indicators that can be used to describe, measure,

assess, document and monitor over time the quality of their energy statistics outputs and make

them available to users. The Energy Statistics Compilers Manual presents several sets of

indicators for consideration and selection for describing the quality of statistical outputs in

general.

9.21. The objective of quality measurement is to have a practical set (limited number) of

quality measures and indicators to describe and monitor over time the quality of the data

produced by the responsible agencies and to ensure that users are provided with a useful

summary of overall quality, while not overburdening respondents with demands for unrealistic

amounts of metadata. As such, it is not intended that all quality measures and indicators be

addressed for all data. Instead, countries are encouraged to select practical sets of quality

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measures and indicators that are most relevant to their specific outputs and can be used to

describe and monitor the quality of the data over time. They should also ensure that the

selected measures and indicators cover each of the quality dimensions that describe their

outputs, have well-established methodologies for their compilation, and are easy to interpret by

both internal and external users. Box 9.2 below presents a sample of some indicators and

measures that countries’ energy statistics programmes can consider using to indicate the quality

of their energy statistics.

9.22. Data compilers should decide how frequently the measures or indicators for different

key outputs are to be produced. Certain types of quality measures and indicators can be

produced for each data item in line with the frequency of production or publication of the data.

For example, response rates for total energy production can be calculated and disseminated

with each new estimate. However, other measures could be produced once for longer periods

and only be produced again for newly released data if there were major changes.

Box 9.2: Selected Indicators for Measuring the Quality of Energy Statistics72

Quality

dimension

Quality measure/indicator

Relevance • Procedures are in place to identify the users of energy data and consult

with them about their needs.

• Unmet user needs - Gaps between key user needs and compiled energy

statistics in terms of concepts, coverage and detail are identified and

addressed.

• Requests for energy information are monitored and the capacity to

respond is evaluated.

• User satisfaction surveys on the agency’s energy statistics outputs are

regularly conducted and the results are analysed and acted upon.

Accuracy and

reliability

• Energy source data are systematically assessed and validated.

• Sampling errors of estimates, e.g. standard errors, are measured,

evaluated and systematically documented.

• Non-sampling errors, e.g. item non-response rates and unit non-response

rates, are measured, evaluated and systematically documented.

• Coverage – The proportion of the population covered by the energy data

collected is assessed.

• The imputation rates are reported.

• Information on the size and direction of revisions to energy data is

provided and made known publicly.

72 The indicators listed represent only a sample of possible indicators that can be used for measuring quality. Refer to

the Energy Statistics Compilers Manual for more information.

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Timeliness and

punctuality

• A published release calendar announces in advance the dates that (key)

energy statistics are to be released.

• The time lag between the end of the reference period and the date of the

first release (or the release of final results) of energy data is monitored

and reported.

• The possibility and usefulness of releasing preliminary data is regularly

considered, while at the same time taking into account the data’s

accuracy.

• The time lag between the date of the release or publication of the data

and the date on which they were announced or promised to be released is

monitored and reported.

• Any divergences from pre-announced release times for the energy data

are published in advance; a new release time is then announced with

explanations on the reasons for the delays.

Coherence and

comparability

• Comparison and joint use of related energy data from different sources

are made.

• Energy statistics are comparable over a reasonable period of time.

• Divergences from the relevant international statistical standards in

concepts and measurement procedures used in the collection/compilation

of energy statistics are monitored and explained.

• Energy statistics are internally coherent and consistent.

Accessibility and

clarity

• Energy statistics and the corresponding metadata are presented in a form

that facilitates proper interpretation and meaningful comparisons, and are

archived.

• Modern information and communication technology (ICT) is mainly

used for disseminating energy statistics; traditional hard copy and other

services are provided, when appropriate, to ensure that users have

appropriate access to the statistics they need.

• An information or user support service, call centre or hotline is

available for handling requests for energy data and for providing answers

to questions about statistical results, metadata, etc.

• Access to energy microdata is allowed for research purposes, subject to

specific rules and protocols on statistical confidentiality.

• The regular production of up-to-date quality reports and methodological

documents (on energy concepts, definitions, scope, classifications, basis

of recording, data sources (including the use of administrative data),

compilation methods, statistical techniques, etc.) is part of the work

programme, and the reports and documents are made known publicly.

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3. Quality reports

9.23. In order for the users of energy statistics to be able to make informed use of the

statistical information provided, they need to know whether the data are of sufficient quality.

For some dimensions of quality, such as timeliness, users are able to easily assess the quality

for themselves, while others, such as coherence and even relevance, may not be as obvious.

The dimension of accuracy in particular is one which users may often have no way of assessing

and must rely on the statistical agency for guidance. A quality report, or similar documentation,

is meant to provide this guidance.

9.24. National practices for reporting on the quality of outputs vary. The quality

documentation provided by data producers can range from short and concise to very detailed,

depending on the users for whom the information is meant. General users will most likely only

be interested in a level of detail necessary for knowing whether the data is reliable, while

producers will want more detailed information to be able to evaluate whether the output meets

the quality requirements and to identify strengths and areas that might need further

improvement.

9.25. Quality information is often structured in a template format to promote comparability

and consistency across statistical domains. Sometimes it is issued in a quality report that is

separate from the other metadata—not as a replacement for, but as a complement to them.

Other times, it may be included as part of other metadata (for example along with explanatory

and technical notes and other more detailed documentation) provided by the compiling agency.

Some compilers refer to it as a quality statement or quality declaration. Typically though, the

quality reports or quality documentation examine and describe quality according to the

dimensions used by the agency to define its products’ fitness for purpose in terms of relevance,

accuracy, reliability, timeliness, punctuality, coherence, comparability, accessibility and clarity,

as focused on in this chapter.

9.26. Two types of quality reports can be distinguished—the shorter “user-oriented” report

and the more detailed “producer-oriented” report. The focus of the user-oriented reports is on

output quality, so they are often limited to brief descriptions of the output dimensions, and

generally include just a few of the indicators for measuring quality listed in the previous

section. On the other hand, the longer “producer-oriented” quality reports, such as the

comprehensive type European Statistical System (ESS) members are recommended to produce

periodically (every five years or so or after major changes), go into greater detail on the

dimensions, especially on errors and other aspects affecting accuracy, and provide additional

information on the processes and other issues, such as confidentiality, costs, and the response

burden. For the users, such details may be confusing and unnecessary for their purposes, but

for the producers, the comprehensive reports serve as an internal self-assessment. Quality

reporting therefore underpins quality assessment, which in turn is the starting point for quality

improvements in statistical programmes. See the Energy Statistics Compilers Manual for more

information on quality reports and descriptions of quality reporting practices.

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9.27. The preparation and updating of quality reports depend on the survey frequency and the

stability of the quality characteristics. Balance should be sought between the need for recent

information and the report compiling burden. If necessary, quality report should be updated as

frequently as the survey is carried out. However, if the characteristics are stable, the inclusion

of quality indicators in the newest survey results could be enough to update the report. Another

option is to provide a detailed quality report less frequently, and a shorter one after each survey,

covering only the updated characteristics, such as some of the accuracy-related indicators.

Countries are encouraged to regularly issue quality reports as part of their metadata.

4. Quality reviews

9.28. Quality reviews can be done in the form of self-assessments, audits or peer reviews.

They can be undertaken by internal or external experts and the timeframe can vary from days

to months, depending on the scope of the review. However, the results are more or less

identical—the identification of improvement actions/opportunities in processes and products. It

is recommended that some form of quality review of energy statistics programmes be

undertaken periodically, for example every four to five years or more frequently, if significant

methodological or other changes in the data sources occur.

9.29. Self-assessments are comprehensive, systematic and regular reviews of an organization's

activities and results are referenced against a model/framework. They are “do it yourself”

evaluations. Typically, self-assessment checklists or questionnaires are developed to be used

for the systematic assessment of the quality of statistical production processes.73

9.30. A quality audit is a systematic, independent and documented process for obtaining

quality evidence concerning the quality of a statistical process and evaluating it objectively to

determine the extent to which policies, procedures and requirements on quality are fulfilled. In

contrast to the self-assessments, audits are always carried out by a third party (internal or

external to the organization). Internal audits are conducted for the purpose of reviewing the

quality system in place (policies, standards, procedures and methods) and the internal

objectives. They are led by a team of internal quality auditors who are not in charge of the

process or product under review. External audits are conducted either by stakeholders or other

parties with an interest in the organization, by an external and independent auditing

organization, or by a suitably qualified expert.

9.31. Peer reviews are a type of external audit which aim to assess a statistical process at a

higher level, not to check conformity with requirements item by item from a detailed checklist.

They are therefore often more informal and less structured than formal external audits.

73 For more information, see for example, the European Statistical System’s Development of a Self-Assessment

Programme (DESAP) and Data Quality Assessment and Tools –

http://ec.europa.eu/eurostat/documents/64157/4373903/07-Checklist-for-Survey-Managers_DESAP-EN.pdf/ec76e3a3-

46b5-409e-a7c3-52305d05bd42.

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Normally, peer reviews do not address specific aspects of data quality but focus rather on

broader organizational and strategic questions. They are typically systematic examinations and

assessments of the performance of one organization by another, with the ultimate goal of

helping the organization under review to comply with established standards and principles,

improve its policy making and adopt best practices. The assessments are conducted on a non-

adversarial basis, and rely heavily on mutual trust among the organization and assessors

involved, as well as their shared confidence in the process.

D. Metadata on energy statistics

9.32. Types of statistical data include microdata, macrodata and metadata. Microdata are non-

aggregated observations or measurements of characteristics of individual units, macrodata are

data derived from microdata by grouping or aggregating them, and metadata are data that

describe the microdata, macrodata or other metadata. This section of the chapter will focus on

metadata.

9.33. Greater emphasis has been given over the years to the importance of ensuring that

statistics published by national statistical offices, international organizations and other data

producing agencies are accompanied by adequate metadata. Metadata, or the “data about data”

(and statistical metadata, the “data about statistical data”), are a specific form of documentation

that defines and describes data so that users can locate and understand them, make an informed

assessment of their strengths, limitations, usefulness and relevance, and use and share them.

Without metadata, statistical data are just numbers.

9.34. Metadata, therefore, are important tools that support the production and final use of

statistical information. The main types of metadata are structural metadata and reference

metadata.

9.35. Structural metadata are identifiers and descriptors of the data that are essential for

discovering, organizing, retrieving and processing statistical datasets. They can be thought of

as the “labels” associated with each data item for it to have meaning, such as the names of the

table columns, unit of measurement, time period, commodity code, etc. Structural metadata

items are an integral part of the statistics database and should be extractable together with any

given data item. If they were not associated with the data, it would be impossible to identify,

retrieve and browse the data.

9.36. Reference metadata describe the content and quality of the statistical data. They are, for

example, conceptual metadata describing concepts used and their practical implementation;

methodological metadata describing methods used for generating the data; and quality

metadata describing the different quality dimensions of the resulting statistics, i.e. timeliness,

accuracy, etc. These reference metadata are often linked (“referenced”) to the data, but unlike

structural data can be presented separately from the data via the Internet or in publications.

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9.37. Metadata items. When disseminating comprehensive energy statistics, the compiling

agency has the responsibility of making the corresponding metadata available and easily

accessible to users. There are numerous metadata items that describe a statistical series, and

many countries and organizations have developed metadata templates, lists or inventories for

the presentation of the concepts, definitions, and descriptions of the methods used in the

collection, compilation, transformation, revision, dissemination and evaluation of their

statistics. One such comprehensive inventory is the Single Integrated Metadata Structure

(SIMS) for metadata and quality reporting in the ESS whose methodological and quality

metadata items are presented below in Box 9.3. In practice, the amount of metadata detail that

different countries disseminate along with their energy data varies, as does the way in which

the metadata are presented. The basic purpose though is always the same—to help users

understand the data and their strengths and limitations.

Box 9.3: Metadata Items for Statistical Releases74

SIMS code Survey/Product name

S.1 Contact (organization, contact person, address, e-mail, phone, fax)

S.2 Introduction

S.3 Metadata update (last certified, last posted and last update)

S.4 Statistical presentation

S.4.1 Data description

S.4.2 Classification system

S.4.3 Sector coverage

S.4.4 Statistical concepts and definitions

S.4.5 Statistical unit

S.4.6 Statistical population

S.4.7 Reference area

S.4.8 Time coverage

S.4.9 Base period

S.5 Unit of measure

S.6 Reference period

S.7 Institutional mandate (legal acts and other agreements, data sharing)

S.8 Confidentiality (policy, data treatment)

S.9 Release policy (release calendar, calendar access, user access)

S.10 Frequency of dissemination

S.11 Dissemination format, Accessibility and clarity (News release, Publications, Online

database, Micro-data access, Other),

S.12 Accessibility of documentation (Documentation on methodology, Quality

documentation)

S.13 Quality management (Quality assurance, Quality assessment)

S.14 Relevance (User needs, user satisfaction, completeness)

74 From the Technical Manual of the Single Integrated Metadata Structure (SIMS)

(http://ec.europa.eu/eurostat/documents/64157/4373903/03-Single-Integrated-Metadata-Structure-and-its-Technical-

Manual.pdf/6013a162-e8e2-4a8a-8219-83e3318cbb39).

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S.15 Accuracy and reliability (Overall accuracy, Sampling error, Non-sampling error

(coverage errors, measurement errors, non-response errors, processing errors, model

assumption errors))

S.16 Timeliness (Time lag - final results) and punctuality (delivery and publication)

S.17 Comparability (geographical, over time)

S.18 Coherence (cross domain, internal)

S.19 Cost and burden

S.20 Data revision (policy, practice)

S.21 Statistical processing

S.21.1 Source data

S.21.2 Frequency of data collection

S.21.3 Data collection

S.21.4 Data validation

S.21.5 Data compilation

S.21.6 Adjustments

S.21.61 Seasonal adjustment

9.38. Users and levels of metadata detail. There are many types of users for any given set of

data. The wide range of possible users, with their different needs and statistical expertise,

means that a broad spectrum of metadata requirements has to be addressed. The responsible

agencies, as data suppliers, must make sufficient metadata available to enable both the least

and the most sophisticated users to interpret and readily assess the data and their quality. It is

recommended that different levels of metadata detail be made available to users to meet the

requirements of the various user groups.

9.39. An approach for presenting metadata is to organize them as if they were in layers within

a pyramid, where the methodological information describing statistics becomes more detailed

as one moves down from the narrower apex (where the summary metadata are) to the wider

base level of the “metadata pyramid” (for the more detailed metadata). In this way, users will

be able to dig as deeply as they want or need to get a more thorough understanding of the

concepts and practices.

9.40. Use of metadata to promote international comparability. Metadata provide a

mechanism for comparing national practices in the compilation of statistics. This may help and

encourage countries to implement international standards and to adopt best practices in the

collection of data in particular areas. The use of standard terminology and definitions and

better harmonization of approaches adopted by different countries will improve the general

quality and coverage of key statistical indicators.

9.41. Statistical Data and Metadata Exchange (SDMX). SDMX technical standards and

content-oriented guidelines provide common formats and nomenclatures for exchanging and

sharing statistical data and metadata using modern technology.75

The development of capacity

75 For more information on SDMX, see http://sdmx.org.

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in countries to disseminate national data and metadata using web technology and SDMX

standards such as cross domain concepts is recommended as a means to standardize and

reduce the international reporting burden.

9.42. Metadata must be a high priority. It is recommended that countries accord high

priority to the development of metadata, to keeping them up-to-date, and to consider the

dissemination of metadata to be an integral part of the dissemination of energy statistics.

Additional country-specific metadata for purposes related to energy statistics will be presented

in the forthcoming Energy Statistics Compilers Manual. In consideration of the integrated

approach to the compilation of economic statistics, it is also recommended that a coherent

system and a structured approach to metadata across all areas of statistics be developed and

adopted, focusing on improving their quantity and coverage.

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Chapter 10. Dissemination

A. Importance of energy statistics dissemination

10.1. The first fundamental principle of official statistics states, inter alia, that “official statistics

that meet the test of practical utility are to be compiled and made available on an impartial basis by

official statistical agencies to honour citizens' entitlement to public information.”76

Dissemination

is an activity for fulfilling this responsibility and refers to the provision to the public of statistical

outputs containing data and related metadata. Energy data are usually disseminated by agencies

responsible for energy statistics in the form of various statistical tables or by providing access to

the relevant databases. However, country practices differ significantly in their effectiveness and

further improvements in this area are necessary.

10.2. Dissemination policy. The dissemination policy should cover a number of issues, including

(a) scope of the data for public dissemination, (b) reference period and data dissemination

timetable, (c) data revision policy, (d) dissemination formats, and (e) dissemination of metadata

and data quality reports. The dissemination policy should be user oriented, reaching and serving

all user groups (central government, public organizations and territorial authorities, research

institutions and universities, private sector, media, general public, and international users), and

provide quality information. While each user group has different needs and preferred data formats,

the goal should be to reach all kinds of users rather than targeting specific audiences. Therefore,

both publications and web sites should be designed as clearly as possible for the general public, as

well as for researchers and the media.

10.3. Users and their needs. With the rapid developments in communication technologies,

information has become a strategic resource for public and private sectors. Improving

dissemination and accessibility of energy statistics is critical to users’ satisfaction. Effective energy

data dissemination is not possible without a good understanding of user needs, as this in many

ways predetermines what data should be considered for dissemination and in which formats. In this

context, countries are encouraged to work closely with the user community by conducting

vigorous outreach campaigns, including building stable and productive relationships with users and

key stakeholders (for example, inviting interested users to become standing customers, actively

helping users to find the statistical information they need and assisting them in the understanding

of the role of energy statistics in sound decision making). In addition, the understanding of user

needs and data requirements will assist in maintaining the relevance of the statistics produced.

76 Available from: http://unstats.un.org/unsd/dnss/gp/fundprinciples.aspx.

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10.4. Users Satisfaction Surveys. User satisfaction surveys are an important tool for detecting

user needs and profiles. User feedback should be integrated into the planning process of official

energy statistics in order to improve its effectiveness. It is recommended that countries conduct

such surveys with the periodicity established by the responsible national agency.

B. Data dissemination and statistical confidentiality

10.5. One important issue official statistics compilers face is the definition of the scope of data

that can be disseminated publicly. The following elements should be taken into account when

disseminating data.

10.6. Statistical confidentiality refers to the protection of data that relate to single statistical units,

and which are obtained directly for statistical purposes or indirectly from administrative or other

sources against any breach of the right to confidentiality. This implies the prevention of unlawful

disclosure. Statistical confidentiality is necessary in order to gain and keep the trust of both those

required to provide data and those using the statistical information. Statistical confidentiality has to

be differentiated from other forms of confidentiality under which information is not provided to the

public, such as, for example, national security concerns.

10.7. Principle 6 of the United Nations Fundamental Principles of Official Statistics provides the

basis for managing statistical confidentiality. It states that “Individual data collected by statistical

agencies for statistical compilation, whether they refer to natural or legal persons, are to be strictly

confidential and used exclusively for statistical purposes.”77

10.8. Legal provisions governing statistical confidentiality at the national level are set forth in

countries’ statistical laws or other supplementary governmental regulations. National definitions of

confidentiality and rules for microdata access may differ but they should be consistent with the

fundamental principle of confidentiality.

10.9. Statistical confidentiality is protected if the disseminated data do not allow statistical units

to be identified either directly or indirectly, thereby disclosing individual information. Direct

identification is possible if data of only one statistical unit are reported in a cell, while indirect

identification or residual disclosure may take place if individual data can be derived from

disseminated data (e.g., because there are too few units in a cell, or because of the dominance of

one or two units in a cell). To determine whether a statistical unit is identifiable, account shall be

taken of all means that might reasonably be used by a third party to identify it. The Energy

Statistics Compilers Manual will contain a separate section on the best country practices in this

respect.

10.10. General rules for protecting confidentiality normally require that the following two factors

be taken into account when deciding on the confidentiality of data: (a) number of units in a

77 Ibid.

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tabulation cell; and (b) dominance of a unit’s or units’ contribution over the total value of a

tabulation cell. The application of these general rules in each statistical domain is the responsibility

of national statistical authorities.

10.11. Methods of protecting confidentiality. As the first step in statistical disclosure control of

tabular data, the sensitive cells need to be identified. Sensitive cells are those that tend to directly

or indirectly reveal information about individual statistical units. Once they have been identified,

the most common practices used for protecting against the disclosure of confidential data include:

(a) Aggregation. A confidential cell in a table is aggregated with another cell and the

information is then disseminated for the aggregate and not for the two individual cells.

This may result, for example, in grouping (and disseminating) data on energy

production at higher levels of SIEC that adequately ensure confidentiality;

(b) Suppression. Suppression means removing records from a database or a table that

contains confidential data. This method allows statisticians to not publish the values in

sensitive cells, while publishing the original values in other cells (called primary

suppression). Suppressing only one cell in a table means, however, that the calculation

of totals for the higher levels to which that cell belongs cannot be performed. In this

case, some other cells must also be suppressed in order to guarantee the protection of

the values in the primary cells, leading to secondary suppression. If suppression is used

to protect confidentiality, then it is important to indicate in the metadata which cells

have been suppressed because of confidentiality;

(c) Other methods. Controlled rounding and perturbation are more sophisticated techniques

for protecting confidentiality of data. Controlled rounding allows statisticians to modify

the original value of each cell by rounding it up or down to a near multiple of a base

number. Perturbation represents a linear programming variant of the controlled

rounding technique.

10.12. Statistical disclosure. Statistical disclosure control techniques are defined as the set of

methods used to reduce the risk of disclosing information on individual units. While application of

such methods occurs at the dissemination stage, they are pertinent to all stages of the process of

statistical production. Statistical disclosure control techniques related to the dissemination step are

usually based on restricting the amount of data or modifying the data release. Disclosure control

methods attempt to achieve an optimal balance between confidentiality protection and the

provision of detailed information. On the basis of available international guidelines78

and national

requirements, countries are encouraged to develop their own statistical disclosure methods that

best suit their specific circumstances.

78 See, for example, Principles and Guidelines for Managing Statistical Confidentiality and Microdata Access,

background document prepared for the Statistical Commission at its thirty-eighth session in 2007 (available at

http://unstats.un.org/unsd/statcom/sc2007.htm).

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10.13. An issue of balance between the application of statistical confidentiality and the need for

public information exists. Balancing the respect for confidentiality and the need to preserve and

increase the relevance of statistics is a difficult issue. It is recognized that legislation on statistical

confidentiality has to be carefully considered in cases where its rigorous application would make it

impossible to provide sufficient or meaningful information to the public. In official energy

statistics, this issue is of particular importance as in many countries the production and distribution

of energy are dominated by a very limited number of economic units.

10.14. The setup of energy balances illustrates the challenge for official energy statistics. If, for

instance, the transformation block of an energy balance cannot be published due to confidentiality,

the quality of such a balance significantly deteriorates, since it will no longer be possible to have

an internally logical energy balance showing the energy flows from production and imports/exports

through transformation to final consumption. The question is how to make it possible to publish

energy balances if there are few units in one part of the balance. The confidentiality issues have to

be addressed.

10.15. Application of confidentiality rules in energy statistics. While recognizing the importance

of the general rules on statistical confidentiality, countries should implement them in such a way as

to promote access to data while ensuring confidentiality, and thus ensure the highest possible

relevance of energy statistics, taking into account their legal circumstances. In this regard, it is

recommended that:

(a) Any information deemed confidential (and that needs to be suppressed) be reported in full

at the next higher level of energy product (or energy flow) aggregation that adequately

protects confidentiality;

(b) Data which are publicly available (e.g., from company reports, publicly available

administrative sources) be fully incorporated and disseminated;

(c) Permission to disseminate certain current data, with or without a certain time delay, be

requested from the concerned data reporters;

(d) Passive confidentiality be considered an option. Passive confidentiality occurs when data

are made confidential only at the request of the concerned economic entity and the

statistical authority finds the request justified based on the adopted confidentiality rules;

(e) Proposals be formulated for including in confidentiality rules the provision that data can

be disseminated if this does not entail excessive damage to the concerned entity. This

implies, consequently, that the rules to determine whether or not “excessive damage”

might take place are clearly defined and publicly available.

C. Reference period and dissemination timetable

10.16. Reference period. It is recommended that countries make their energy data available on a

calendar basis compatible with the practice adopted by the statistical authority of the compiling

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country in other areas of statistics, preferably according to the Gregorian calendar and consistent

with the recommendations set out in this publication. For international comparability, countries that

use the fiscal year should undertake efforts to report annual data according to the Gregorian

calendar.

10.17. Data dissemination timetable. In producing statistical information, there is usually a trade-

off between the timeliness with which the information is prepared and the accuracy and level of

detail of the published data. A crucial factor, therefore, in maintaining good relations between

producers of energy statistics and the user community is developing and adhering to an appropriate

release schedule. It is recommended that countries announce in advance the precise dates on

which various series of energy statistics will be released. This advance release schedule should be

posted at the beginning of each year on the website of the national agency responsible for the

dissemination of the official energy statistics.

10.18. The most important elements that should be taken into account in determining the

compilation and release schedule of energy statistics include:

(a) The timing of the collection of initial data by various source agencies;

(b) The extent to which data derived from the major data sources are subject to revisions;

(c) The timing of preparation of important national economic policy documents that need

energy statistics as inputs; and

(d) The mode(s) of data dissemination (press release, online access, or hard copy).

10.19. Timeliness is the amount of time between the end of the reference period to which the

data pertain, and the date on which the data are released. The timeliness of the release of

monthly, quarterly and annual energy statistics varies greatly from country to country, mainly

reflecting different perspectives on timeliness, reliability, accuracy and trade-offs between

them, but also the differences in available resources and in the efficiency and effectiveness of

the statistical production process. From the user perspective, the value of energy data increases

significantly when they are released with the shortest possible delay. Countries should

undertake systematic efforts to comply with this user demand. However, taking into account

both policy needs and prevailing data compilation practices, countries are encouraged to:

(a) Release their monthly data (e.g., on totals of energy production, stocks and stock

changes), within two calendar months after the end of the reference month, at least at

the most aggregated level;

(b) Release their quarterly data within three calendar months after the end of the reference

quarter; and

(c) Release their annual data within fifteen calendar months after the end of the reference

year.

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10.20. The early release of provisional estimates within one calendar month for monthly data on

specific flows and products and within nine to twelve calendar months for annual data is

encouraged, provided countries are capable of doing this.

10.21. If countries use additional information for the compilation of annual energy statistics, the

data for the fourth quarter (or for the twelfth calendar month) should be compiled and disseminated

in their own right and not be derived as the difference between the annual totals and the sum for the

first three quarters (or eleven calendar months) in order to provide undistorted data for all months

and quarters.

D. Data revision

10.22. Revisions are an important part of the compilation of energy statistics. While the

compilation and dissemination of provisional data often improve the timeliness of energy

statistics and its relevance, the provisional data should be revised when new and more accurate

information becomes available. Such practice is recommended if countries can ensure

consistency between provisional and final data. Although, in general, repeated revisions may

be perceived as reflecting negatively on the reliability of official energy statistics, an attempt to

avoid this by producing accurate but untimely data will ultimately fail to satisfy users’ needs.

Revisions affect both annual and short-term energy statistics but they are often more significant

for short-term data.

10.23. In general, two types of revisions are distinguished: (a) routine, normal or concurrent

revisions that are part of the regular statistical production process and which aim to incorporate

new or updated data or to correct data or compilation errors; and (b) major or special revisions

that are not part of the regular revision schedule and which are conducted in order to

incorporate major changes in concepts, definitions, classifications and changes in data sources.

10.24. With respect to routine revisions, it is recommended that countries develop a revision

policy that is synchronized with the release calendar. The description of such a policy should

be made publicly available. Agencies responsible for official energy statistics may decide to

carry out a special revision, in addition to the normal statistical data revisions, for the purpose

of reassessing the data or investigating in depth some new economic structures. Such revisions

are carried out at longer, irregular intervals. Often, they may require changes in the time series

going as far back as its beginning to retain methodological consistency. It is recommended

that these revisions should be subject to prior notification to users to explain why revisions are

necessary and to provide information on their possible impact on the released outputs.

10.25. Countries are encouraged to develop a revision policy for energy statistics that is

carefully managed and well coordinated with other areas of statistics. That policy should be

aimed at providing users with the information necessary for coping with revisions in a

systematic manner. The absence of coordination and planning of revisions is considered a

quality problem by users. Essential features of a well-established revision policy are

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predetermined release and revision schedules, reasonable stability from year to year, openness,

advance notice of reasons and effects, easy access to sufficiently long time series of revised

data, as well as adequate documentation of revisions included in statistical publications and

databases. A sound revision policy is recognized as an important aspect of good governance in

statistics, as it will not only help the national users of the data but will also promote

international consistency.79

The future Energy Statistics Compilers Manual will provide

detailed information on good practices in revision policy.

E. Dissemination formats

10.26. A key to the usefulness of energy statistics is the availability of data and hence their broad

dissemination. Data can be disseminated both electronically and in paper publications. It is

recommended that energy statistics be made available electronically, but countries are

encouraged to choose the dissemination format that best suits their users’ needs. For example,

press releases of energy statistics must be disseminated in ways that facilitate re-dissemination by

mass media; and more comprehensive or detailed statistics need to be disseminated in electronic

and/or paper formats. Regular data dissemination should satisfy most, if not all user needs, and

customized data sets would be provided only in exceptional cases. It is advisable that countries

ensure that users are clearly made aware of the procedures and options for obtaining the required

data.

10.27. Dissemination of metadata. The provision of adequate metadata and quality assessments of

energy statistics is as important to users as the provision of data itself. Countries are encouraged to

harmonize their data with international standards, follow the recommendations provided in Chapter

9 on data quality assurance and metadata for energy statistics and develop and disseminate

metadata in accordance with the recommendations provided. Countries might wish to consider

developing different levels of detail of metadata to facilitate access and use.80

F. International reporting

10.28. It is recommended that countries disseminate their energy statistics internationally as soon

as they become available to national users and without additional restrictions. To ensure a speedy

and accurate data transfer to international and regional organizations, it is recommended that

countries use the Statistical Data and Metadata Exchange (SDMX)81

format in the exchange and

sharing of their data.

79 For examples of good practices, see Organisation for Economic Co-operation and Development Data and Metadata

Reporting and Presentation Handbook (Paris, 2007), chap.7.

80 For further details on data and metadata reporting, see Organisation for Economic Co-operation and Development,

Data and Metadata Reporting and Presentation Handbook (Paris, 2007). 81 The SDMX technical standards and content oriented guidelines can provide common formats and nomenclatures for

exchange and sharing of statistical data and metadata using modern technology. The dissemination of national data and

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metadata using web technology and SDMX standards is encouraged as a means to reduce the international reporting

burden and to increase the efficiency of the international data exchange. For additional information on SDMX, see

http://www.sdmx.org/.

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Chapter 11. Uses of Basic Energy Statistics and Balances

A. Introduction

11.1 This chapter illustrates the different uses of the data items presented in Chapter 6 and

the energy balances presented in Chapter 8 in the compilation of other statistics or for

indicators related to energy statistics.

11.2 Section B presents a brief description of the energy accounts of the System of

Environmental-Economic Accounting for Energy (SEEA-Energy). The section describes the

main differences in concepts and definitions between energy balances and energy accounts, the

main adjustments needed to link the two systems and the need for additional data items that

will allow the compilation of energy accounts from energy balances.

11.3 Section C describes a list of energy indicators as an important tool for monitoring

policies. Most of these indicators can be derived from the data items presented in Chapter 6.

11.4 Section D provides some reference for the use of basic energy statistics and balances in

the calculation of energy-related greenhouse gas emissions. Methods for the calculation of such

emissions are discussed here, although details are not provided and the user is referred to the

Intergovernmental Panel on Climate Change (IPCC) guidelines instead.

B. The System of Environmental-Economic Accounting for Energy

11.5 The forthcoming SEEA-Energy provides a conceptual framework for organizing

energy-related information in a coherent manner consistent with the concepts, definitions and

classifications of the System of National Accounts (SNA).82

It supports analyses of the role of

energy within the economy and the relationship between energy-related activities and the

environment. SEEA-Energy consists of three main types of accounts, namely:

(a) Physical flow accounts in which flows of energy are recorded in energy units. They

record the flow of energy from natural inputs from the environment to the economy,

within the economy (as energy products) and from the economy to the environment (as

losses and returns of energy to the environment). The various energy flows are recorded

in the physical supply and use table (PSUT).

(b) Monetary flow accounts for energy-related transactions which record the monetary

transactions related to physical flows of energy in a supply and use table framework.

82 More information on SEEA-Energy is available online at http://unstats.un.org/unsd/envaccounting/seeae/

166

These accounts focus on the transactions within the economy and therefore do not cover

flows between the environment and the economy.

(c) Asset accounts in physical and monetary terms which describe stocks83

at the beginning

and end of the accounting year and the changes therein. The asset accounts are

compiled for mineral and energy resources and provide information on the availability

of the resource in the environment, its extraction pattern and depletion rate.

1. Main differences between energy balances and energy accounts

11.6 The main differences between energy balances and energy accounts are presented in

three groups: conceptual differences, differences in terminology and presentational differences.

Conceptual differences

11.7 The main conceptual difference between energy balances and accounts is the

geographical coverage. The reference territory for energy balances is the national territory and

statistics are compiled for all units physically located in that territory. Units physically located

outside the territory are considered to be part of the rest of the world. This coverage is referred

to as the territory principle.

11.8 Energy accounts, on the other hand, use a geographic coverage based on all institutional

units that are residents of a particular national economy—independent of where they are

physically located. Units that are not resident units are considered to be part of the rest of the

world. This geographical coverage is referred to as the residence principle. An institutional unit

is considered a resident unit of a country when its centre of predominant economic interest is

within the economic territory of the country.84

Generally, the economic territory will align with

the physical boundary of a country but adjustments are made for embassies, consulates,

military bases, scientific stations and the like, which belong only to the economic territory of

the country they represent.

11.9 The use of the territory or residence principle leads to differences in the way certain

statistics are recorded (e.g., imports/exports/use, international bunkers, etc.).

11.10 The use of the territory principle implies that imports and exports cover all transactions

between units physically present in the territory and units physically located outside the

territory, independent of the residence status of the units involved (thus trade follows the

physical movement of the goods). In addition, transactions between units physically located

within the territory are never recorded as imports/exports even if the residence status of the

units involved differs. Using the residence principle in energy accounts, however,

83 Stocks should be understood here in the SEEA sense, covering mineral and energy resources, while in IRES the term

would be used for energy products, referring to the given quantity of each resource or product at a given point in time.

84 2008 SNA paras. 4.10-4.14

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imports/exports cover transactions between resident and non-resident units independent of the

location where the transaction occurs, whether it is abroad (e.g. in the case of national tourists

abroad), or in the national territory (e.g. in the case of foreign companies refueling inland).

11.11 The same goes for recording the uses of products. While in the energy balance the use

of energy in the territory covers the use by all units physically located in the territory, in energy

accounts, it covers only the use of units resident in the national economy—the use by non-

resident units is recorded as an export (provided that the supplying unit is considered resident).

In addition, in energy accounts the use of energy products would also include the use by

resident units abroad, with the counterpart transaction on the supply side being an import. This

is the case, for example, of residents who refuel their own vehicles abroad and ships operated

by residents which are refueled abroad.

Differences in terminology

11.12 There are differences in the use of certain terms in energy accounts and energy

balances. For example, terms such as “supply”, “final consumption”, “stocks” and “stock

changes” are well defined in both balances and accounts but their definitions differ.

11.13 Supply. In energy balances, the term supply represents energy entering the national

territory for the first time, less energy exiting from the national territory (through exports or

international bunkering) and stock changes. Thus

Total energy supply = Primary energy production

+ Import of primary and secondary energy

- Export of primary and secondary energy

- International (aviation and marine) bunkers

- Stock Changes

11.14 In energy accounts, the term supply is defined as the sum of the production of primary

energy and imports (according to the residence principle) of energy products.85

Thus, exports,

international bunkers and stock changes, together with intermediate consumption and capital

formation are all considered uses. In addition, international bunkering is recorded in the energy

accounts as intermediate consumption if the bunkering is undertaken by a ship operated by a

resident unit, or as exports if the ship is operated by a non-resident unit.

11.15 Final consumption. In energy balances final consumption refers to the use of fuel,

electricity and heat delivered to final consumers of energy for both their energy and non–

energy uses. It excludes the use of energy products in energy industries (and by other energy

producers) as input into transformation and energy industries own use. In energy accounts, the

85 See SEEA-Energy Chapter 7. It should be noted though that the term “Total supply” is also defined and used

differently in other chapters of SEEA-Energy.

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term “final consumption” is used to denote the use of goods and services by individual

households or the government to satisfy their individual or collective needs or wants. However,

when the goods and services are used as inputs to the production process by economic units,

this is referred to as “intermediate consumption”.

11.16 Stocks and stock changes. The concepts of stocks and stock changes defined in energy

balances correspond to ‘inventories’ and ‘changes in inventories’ in SEEA-Energy (and 2008

SNA). In addition, the stock changes appear in the balances as part of the total supply, while in

the energy accounts they appear as part of use.

Presentational differences

11.17 In the standard tables of energy accounts, the presentation of statistics for economic

activities and households strictly follows the principles of classification and the structure of the

International Standard Industrial Classification of All Economic Activities (ISIC Rev. 4). Thus,

information on any specific enterprise/establishment (be it on the production or on the

consumption side) is presented under the ISIC category of the principal activity of the unit

involved. Energy balances, however, do not follow the same principle, as information on a

specific enterprise/establishment is not completely linked to the relevant ISIC category of the

unit involved. Rather, it is presented in different sections of the balances depending on the type

of use and the ISIC category of the unit involved.

11.18 A typical example is the use of energy for transport purposes. While detailed

information on the use of energy for transport and other purposes is collected from individual

statistical units, data are shown in different ways in energy balances and energy accounts. In

energy accounts, data are presented strictly by ISIC category of the statistical units involved,

showing transport and other uses of energy within the ISIC class of the unit involved. In energy

balances on the other hand, a total aggregate for “transport” is introduced, showing the total

energy use for transport purposes by all economic activities, broken down into modes of

transport. As a result, the portion of energy used for transport purposes by individual ISIC

industries is not included in the other aggregates for final consumption of energy (such as for

wholesalers or manufacturers) in energy balances.86

11.19 Another example is the energy used for producing other energy products. While energy

accounts follow strict ISIC categories, energy balances record energy that is transformed into

different products in the entry “transformation” (broken down by transformation technology),

and energy consumed to support energy production in the entry “energy industries own use”.

11.20 The energy balance allows for the balancing item ‘Statistical difference’, while the

energy accounts, by design, do not allow for discrepancy between supply and use. In cases

86 For more details, see chapter 8 of this publication.

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where there is a difference between supply and use, reconciliation and allocation of this

quantity to specific flows are needed to reduce or eliminate any discrepancies.

2. Adjustments for the compilation of energy accounts

11.21 Basic energy statistics and energy balances can be used as a data source for the

compilation of the SEEA-Energy physical supply and use tables. However, because of the

differences in concepts and definitions, adjustments are needed in order to compile the energy

accounts.

11.22 Adjustments on imports/exports. In order to include imports and exports from the energy

balances into the energy accounts, adjustments are needed to relate them to transactions

between resident and non-resident units, such as the inclusion of fuel purchases by residents

abroad as imports.

11.23 Other adjustments for geographical coverage. Other examples relate to the case for

international marine and aviation bunkering and for items in the bottom block of the balances.

In addition, the different uses of energy products of energy balances need to be disaggregated

so that they can be recorded as intermediate/final consumption when the unit is resident or

export when the unit is non-resident, and complemented with the use by resident units abroad.

This is similar to the case of international bunkering.

11.24 It should also be noted that, in principle, some additional adjustments might be

necessary to the geographical coverage to exclude foreign territorial enclaves in the national

territory and/or include national territorial enclaves in the rest of the world. These areas are

clearly demarcated land areas (such as embassies, consulates, etc.) located in other territories

and used by governments that own or rent them for diplomatic, military or scientific purposes.

These areas are excluded from the basic statistics and energy balances when located abroad,

whereas foreign enclaves are included when located in the national territory. For statistics

presented by the accounting framework, on the contrary, national enclaves in the rest of the

world are included, while foreign enclaves in the national territory are excluded.

11.25 Reallocation/regrouping of data to the relevant ISIC category. In order to compile

energy accounts, information has to be regrouped according to the different ISIC categories.

Information on “transformation”, “transport”, “non-energy use”, “energy industries own use”

and “primary production” are examples of items that need to be reallocated in order to present

information on a purely ISIC-based tabulation, such as that used in SEEA-Energy.

11.26 Bridge tables may be constructed to clearly show the links for the total supply and total

use of the different products between the energy accounts and the energy balances.

Additional data items necessary for the compilation of energy accounts

11.27 In order to compile energy accounts, it is important to have information that allows for

the adjustments presented in the previous section. Such information includes, for example, the

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breakdown of deliveries for international bunkering of resident and non-resident units,

deliveries to resident and non-resident final consumers, and the use of energy products by

resident units abroad.

11.28 In view of the above differences, countries are encouraged to clearly document and

make available the methods used for the reallocation and adjustment of data provided by basic

energy statistics and balances to energy accounts.

C. Energy indicators

11.29 Energy indicators are a useful tool for summarizing information and monitoring trends

reflecting various aspects of a country’s energy situation over time. A number of indicators can

be compiled from basic energy statistics, energy balances and energy accounts.

11.30 The choice of the set of indicators compiled by a country depends on national

circumstances and priorities, sustainability and development criteria and objectives, as well as

data availability.

11.31 Examples of core indicators for sustainable development are provided in a joint

publication by several international organizations.87

These indicators are organized in three

dimensions, social, economic and environmental, as well as according to theme and sub-theme.

Tables 11.1-11.3 present energy indicators organized according to these three dimensions.88

Most of them can be derived from the data items presented in Chapter 5. However, for some of

them additional information needs to be collected/compiled (e.g., persons and/or freight

tonnage transported times distance travelled, floor area, etc.).

11.32 There is a growing interest in energy efficiency indicators and work is being carried out

(most notably by the International Energy Agency) to review current practices at the national

level and provide guidance on concepts and methods. While the importance of these indicators

is recognized, many require additional levels of detail than that presented in the list of data

items in Chapter 6 and therefore not all are presented in this chapter.

87 Energy indicators for sustainable development: guidelines and methodologies. IAEA, UNDESA, IEA, Eurostat,

EEA, Vienna, 2005

88 Since this publication precedes the work on IRES, the terminology used for the data items is not always compliant

with IRES.

171

Table 11.1: Energy Indicators linked to the social dimension

Theme Sub-theme Energy Indicator Components

Equity Accessibility SOC1 Share of households (or population) without electricity or commercial

energy, or heavily dependent on non-

commercial energy

– Households (or population) without electricity or

commercial energy, or heavily

dependent on noncommercial

energy

– Total number of households or

population Affordability SOC2 Share of household income spent on

fuel and electricity

– Household income spent on

fuel and electricity

– Household income (total and

poorest 20% of population)

Disparities SOC3 Household energy use for each income

group and corresponding fuel mix

– Energy use per household for

each income group (quintiles) – Household income for each

income group (quintiles) –

Corresponding fuel mix for each

income group (quintiles)

Health Safety SOC4 Accident fatalities per energy produced

by fuel chain

– Annual fatalities by fuel chain

– Annual energy produced

Table 11.2: Energy Indicators linked to the economic dimension


Use and Production

Patterns

Overall Use ECO1 Energy use per capita – Energy use (total primary energy supply, total final

consumption and electricity use)

– Total population

Overall

Productivity

ECO2 Energy use per unit of GDP – Energy use (total primary

energy supply, total final

consumption and electricity use)

– GDP

Supply Efficiency

ECO3 Efficiency of energy conversion and distribution

– Losses in transformation systems, including losses in

electricity generation,

transmission and distribution

Production ECO4 Reserves-to-production ratio – Proven recoverable reserves

– Total energy production

ECO5 Resources-to-production ratio – Total estimated resources

– Total energy production

End Use ECO6 Industrial energy intensities – Energy use in industrial sector

and by manufacturing branch

– Corresponding value added

ECO7 Agricultural energy intensities – Energy use in agricultural

sector – Corresponding value added

ECO8 Service/ commercial energy intensities – Energy use in service/

commercial sector

– Corresponding value added

172

ECO9 Household energy intensities – Energy use in households and

by key end use

– Number of households, floor area, persons per household,

appliance ownership

ECO10 Transport energy intensities – Energy use in passenger travel

and freight sectors and by mode

– Passenger-km travel and

tonne-km freight and by mode

Diversification

(Fuel Mix)

ECO11 Fuel shares in energy and electricity – Primary energy supply and

final consumption, electricity generation and generating

capacity by fuel type

– Total primary energy supply,

total final consumption, total

electricity generation and total

generating capacity ECO12 Non-carbon energy share in energy and

electricity

– Primary supply, electricity

generation and generating

capacity by non-carbon energy


total electricity generation and

total generating capacity

ECO13 Renewable energy share in energy and

electricity

– Primary energy supply, final

consumption and electricity

generation and generating

capacity by renewable energy


total final consumption, total electricity generation and total

generating capacity

Prices ECO14 End-use energy prices by fuel and by

sector

– Energy prices (with and

without tax/subsidy)

Security Imports ECO15 Net energy import dependency – Energy imports

– Total primary energy supply

Strategic Fuel

Stocks

ECO16 Stocks of critical fuels per

corresponding fuel consumption

– Stocks of critical fuel (e.g., oil,

gas, etc.)

– Critical fuel consumption

Table 11.3: Energy Indicators linked to the environmental dimension


Atmosphere Climate Change ENV1 GHG emissions from energy

production and use per capita and per unit of GDP

– GHG emissions from energy

production and use – Population and GDP

Air Quality ENV2 Ambient concentrations of air

pollutants in urban areas

– Concentrations of pollutants in

air

ENV3 Air pollutant emissions from energy

systems

– Air pollutant emissions

Water Water Quality ENV4 Contaminant discharges in liquid

effluents from energy systems,

including oil discharges

– Contaminant discharges in

liquid effluents

173

Land Soil Quality ENV5 Soil area where acidification exceeds

critical load

– Affected soil area

– Critical load

Forest ENV6 Rate of deforestation attributed to energy use

– Forest area at two different times

– Biomass utilization

Solid Waste

Generation and

Management

ENV7 Ratio of solid waste generation to units

of energy produced

– Amount of solid waste

– Energy produced

ENV8 Ratio of solid waste properly disposed

of to total generated solid waste

– Amount of solid waste

properly disposed of

– Total amount of solid waste

ENV9 Ratio of solid radioactive waste to units of energy produced

– Amount of radioactive waste (cumulative for a selected period

of time)

– Energy produced

ENV10 Ratio of solid radioactive waste awaiting disposal to total generated

solid radioactive waste

– Amount of radioactive waste awaiting disposal

– Total volume of radioactive

waste

11.33 It should be noted that the list of indicators presented in this chapter is not exhaustive.

Countries are encouraged to develop the list of relevant indicators according to their policy

concerns and data availability.

D. Greenhouse gas emissions

11.34 The availability of good, reliable and timely basic energy statistics and energy balances

is fundamental for the estimation of greenhouse gas (GHG) emissions and to address the global

concerns for climate change. Basic energy statistics and energy balances are the main sources

of data for the calculation of energy-related GHG emissions, as the IPCC Guidelines are based

on the same conceptual framework. Countries are encouraged to make additional efforts to

verify the compiled data and make any necessary adjustments to ensure that the calculated

emissions are internationally comparable.

1. Climate change and GHG emissions

11.35 Human interference with the climate system, driven by the so-called “greenhouse

effect”, started being acknowledged as a global problem in 1979, at the First World Climate

Conference. Ten years later, in 1988, the Intergovernmental Panel on Climate Change (IPCC)

was established by the United Nations Environment Programme (UNEP) and the World

Meteorological Organization (WMO), with a mission to provide a clear scientific view of the

knowledge in climate change and its potential environmental and socio-economic impacts.

174

11.36 The latest available scientific assessment of climate change from IPCC is provided in

the IPCC Fifth Assessment Report (AR5), published in 2013. The report underlines that

“warming of the climate system is unequivocal” and that “it is extremely likely that more than

half of the observed increase in global average surface temperature from 1951 to 2010 was

caused by the anthropogenic increase in greenhouse gas concentrations and other

anthropogenic forcings together.” The AR5 not only corroborated, but reinforced the findings

of the IPCC Fourth Assessment Report (AR4), published in 2007. These assessments are

consistent with ongoing climate observations reported by WMO. For the future, IPCC AR5

emphasizes that “continued emissions of GHGs will cause further warming and changes in all

components of the climate system”, and that “limiting climate change will require substantial

and sustained reductions of greenhouse gas emissions.”

11.37 The international community responded to the growing concerns about climate change

by putting in place three key international treaties: the United Nations Framework Convention

on Climate Change (UNFCCC), the Kyoto Protocol to UNFCCC and the Paris Agreement

under UNFCCC. Reporting on GHG emissions, including emissions from the energy sector, is

a key obligation of the Parties to these treaties.

2. IPCC guidelines for estimating GHG emissions

11.38 An important function of IPCC is to provide methodological guidance on the estimation

of national GHG emissions as part of the preparation of national GHG inventories. The first

consolidated and extensive guidance on the estimation of GHG emissions was issued by IPCC

in 1995, and revised and published as the Revised 1996 IPCC Guidelines for National

Greenhouse Gas Inventories (IPCC 1997). Later, it was followed by the Good Practice

Guidance and Uncertainty Management in National Greenhouse Gas Inventories (IPCC 2000)

and the Good Practice Guidance for Land Use, Land-Use Change and Forestry (IPCC 2003).

11.39 The 2006 IPCC Guidelines for National Greenhouse Gas Inventories were prepared at

the invitation of UNFCCC. According to decision 24/CP.19 of the Conference of the Parties to

UNFCCC (Warsaw, Poland, 11-23 November 2013), Annex I Parties to UNFCCC shall use the

2006 IPCC Guidelines in their national GHG inventory submissions from 2015. While there is

no formal decision on the use of the 2006 IPCC Guidelines by non-Annex I Parties to date,

some developing countries have started using the Guidelines in preparing national submissions

on climate change. It is likely that more and more developing countries will start using the

2006 IPCC Guidelines in the near future.

11.40 The IPCC Guidelines address emissions of direct and indirect GHGs. The direct GHGs

covered by the Guidelines are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O),

hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6) and some

others. The indirect GHGs considered in the Guidelines are nitrogen oxides (NOX), ammonia

(NH3), non-methane volatile organic compounds (NMVOC), carbon monoxide (CO) and

sulphur dioxide (SO2).

175

11.41 The methods for estimating GHG emissions in the IPCC Guidelines are structured into a

three tier sectoral approach and a reference approach. These methods are briefly described in

Box 11.1.

Box 11.1: Methods for the estimation of GHG emissions from fossil fuel combustion

Sectoral approach

Tier 1 method

The Tier 1 method is used to estimate emissions from all sources of combustion on the basis of the

quantities of fuel combusted (usually taken from national energy statistics) and average (default)

emission factors. This method is fairly accurate for CO2 emissions, but much less so for non-CO2

gases because emission factors for these gases may depend considerably on the combustion

technology and operating conditions.

Tier 2 method

In the Tier 2 method for energy, emissions from combustion are estimated from similar fuel

statistics as in the Tier 1 method, but country-specific emission factors are used instead of the Tier

1 defaults. Since available country-specific emission factors might differ for different fuels,

combustion technologies or individual plants, activity data could be further disaggregated to

properly reflect such disaggregated sources. Tier 2 estimates can be more accurate than Tier 1

estimates but require more data.

Tier 3 method

In the Tier 3 method for energy, either detailed emission models or measurements and data at

individual plant level are used where appropriate. Properly applied, the Tier 3 method should

provide better estimates, especially for non-CO2 emissions, though at the cost of more extensive

data requirements and greater estimation efforts.

Reference approach

The Reference Approach, which is applied to CO2 emissions from fuel combustion, can be used as

an independent check of the sectoral approach and as a first-order estimate of national GHG

emissions. This is a ‘’top-down’ approach assuming that all carbon coming into a national

economy is either released into the atmosphere in the form of a greenhouse gas, or diverted (e.g.,

into increases of fuel stocks). The Reference Approach methodology is implemented in 5 steps:

Step 1: Estimate apparent fuel consumption in original units

Step 2: Convert to a common energy unit

Step 3: Multiply by carbon content to compute the total carbon

Step 4: Compute the excluded carbon

Step 5: Correct for unoxidised carbon and convert to CO2 emissions

The Reference approach requires statistics on the production of fuels, on their external trade, as

well as on changes in their stocks. It also requires some data on the consumption of fuels used for

non-energy purposes.

176

3. Energy emissions and energy statistics

11.42 The “energy sector” in the IPCC definition includes exploration and exploitation of

primary energy sources, conversion of primary energy sources into more useable energy forms

in refineries and power plants, transmission and distribution of fuels, and the use of fuels in

stationary and mobile applications. In terms of emission sources, two major categories are

distinguished:

a. Emissions from fuel combustion (which are further disaggregated into the sub-

categories of Energy Industries, Manufacturing Industries and Construction, Transport,

Other Sectors, and Non-specified);

b. Fugitive emissions, which are intentional or unintentional releases of gases

during the production, processing, transmission, storage and use of fuels (further

disaggregated into emissions from solid fuels (such as methane emissions from coal

mining) and emissions from oil and natural gas).

11.43 The energy sector is the major source of GHG emissions. According to the IPCC AR5,

around 70 per cent of global GHG emissions in 2010 related to energy supply and use, with

CO2 from fuel combustion accounting for a major part. Therefore, it is important, even critical,

to accurately estimate energy-related emissions and CO2 emissions, in particular.

11.44 Estimates are normally done at the level of individual emission sources which may

correspond to a physical facility (e.g. a power plant) or to an industrial or economic group (e.g.

cement production). These estimates are then summed up to obtain sectoral and national totals

by individual gases, as well as the total of all gases calculated as a weighted average in terms

of the so-called CO2-equivalent. The number of individual source categories may vary

depending on data availability, the organizational and methodological frameworks of the

assessment, and the resources available. For each individual source category, CO2 emissions

are often estimated using an equation of the type shown below:

.tech,fuelfuelfuel FactorEmission Combusted FuelEmissions ×=

where Emissionsfuel are CO2 emissions by type of fuel (for a given source category),

FuelCombustedfuel is the quantity of fuel combusted, and Emission Factorfuel,tech. is the CO2

emission factor by type of fuel and combustion technology used. Sometimes a carbon oxidation

factor is added to this equation. While the equation is simple, estimating values for the amount

of fuel combusted and selecting emission factors consistent with the definitions of the IPCC

emission categories may be difficult.

11.45 Regardless of the tier used, consumption of fuels by fuel/product type is the very first

basic step in the estimation of CO2 emissions from fuel combustion. If this basic step is not

done properly, the subsequent steps cannot result in an accurate estimate. Data on the

production and consumption of fuels and energy products are part of national energy statistics,

normally in the form of national energy balances. It is therefore unequivocal that the quality of

177

GHG estimates depends critically on the quality of national energy statistics. This dependence

is fully recognized by the IPCC Guidelines, which encourage the use of fuel statistics collected

by official national bodies, as this usually provides the most appropriate and accessible data.

11.46 If national data sources are unavailable or have gaps, IPCC suggests using data from

international organizations (based normally on national submissions from countries). The two

main sources of international energy statistics are the United Nations Statistics Division

(UNSD) and the International Energy Agency (IEA). Both collect data from the national

administrations of their member countries through questionnaires (thus collecting “official

data”) and they exchange data to ensure consistency and prevent duplication of efforts by

reporting countries.

11.47 Estimating non-CO2 emissions from fuel combustion normally requires more specific

methods than for CO2 emissions and more detailed information, such as the characteristics of

fuel composition, combustion conditions, combustion technologies and emission control

methods. Specific methods and data are also used for estimating fugitive CO2 and non-CO2

emissions. Such methods and associated data requirements can be found in the corresponding

sections of the IPCC Guidelines. It is quite clear also in the Guidelines that for these emissions

national energy statistics are indispensable for obtaining a solid emissions estimate.

11.48 A number of references related to GHG emission estimates are provided in the

bibliography to this publication.

178

Annex A. Primary and Secondary products; Renewables and Non-renewables

Energy statistics conventionally distinguishes between primary and secondary energy products,

and between renewable and non-renewable products (see Chapter 2 for definitions and other

details). The cross-classification of these categories of energy products and their list are provided

below.

Cross-classification of primary/secondary and renewable/non-renewable products

Primary products Secondary products

No

n-r

enew

ab

les

01 - Hard coal

02 - Brown coal

11 - Peat

20 - Oil shale

30 - Natural gas

41 - Conventional crude oil 42 - Natural gas liquids (NGL)

44 - Additives and oxygenates

61 - Industrial waste

62 (partially)1 - Municipal waste

Nuclear Heat Heat from chemical processes

03 - Coal products

12 - Peat products

43 - Refinery feedstocks

46 - Oil products

Electricity and heat from combusted fuels of fossil

origin

Electricity derived from heat from chemical

processes and nuclear heat Any other product derived from primary/secondary

non-renewable products

Ren

ewa

ble

s

5 - Biofuels (except charcoal)

62 (partially) - Municipal waste

Heat from renewable sources, except from

combusted biofuels Electricity from renewable sources, except from

geothermal, solar thermal or combusted biofuels2

516 - Charcoal

Electricity and heat from combusted biofuels

Electricity from geothermal and solar thermal

Any other product derived from primary/secondary

renewable products

1 The part of municipal waste coming from biomass origin is considered as renewable, whereas the part coming from

fossil origin is considered as non-renewable.

2 Renewable sources for electricity are comprised of: hydro, wind, solar (photovoltaic and solar thermal), geothermal,

wave, tide and other marine energy, as well as the combustion of biofuels. Renewable sources for heat are: solar

thermal, geothermal and the combustion of biofuels.

179

List of primary/secondary and renewable/non-renewables

It should be noted that at the time of publication no internationally agreed definition of renewable

and non-renewable products was available. Therefore, the list provided below is indicative and

subject to amendments.

Primary (P) Renewable (R) SIEC Headings Secondary (S) Non Renewable (NR)

0 Coal NR 01 Hard coal P NR 011 0110 Anthracite P NR 012 Bituminous coal P NR

0121 Coking coal P NR 0129 Other bituminous coal P NR 02 Brown coal P NR 021 0210 Sub-bituminous coal P NR 022 0220 Lignite P NR 03 Coal products S NR 031 Coal coke S NR 0311 Coke oven coke S NR 0312 Gas coke S NR 0313 Coke breeze S NR 0314 Semi cokes S NR 032 0320 Patent fuel S NR 033 0330 Brown coal briquettes (BKB) S NR 034 0340 Coal tar S NR 035 0350 Coke oven gas S NR 036 0360 Gas works gas (and other manufactured gases for

distribution) S NR

037 Recovered gases S NR 0371 Blast furnace gas S NR 0372 Basic oxygen steel furnace gas S NR 0379 Other recovered gases S NR 039 0390 Other coal products S NR 1 Peat and peat products NR 11 Peat P NR 111 1110 Sod peat P NR 112 1120 Milled peat P NR 12 Peat products S NR 121 1210 Peat briquettes S NR 129 1290 Other peat products S NR 2 Oil shale / oil sands P NR 20 Oil shale / oil sands P NR 200 2000 Oil shale / oil sands P NR 3 Natural gas P NR 30 Natural gas P NR 300 3000 Natural gas P NR 4 Oil NR 41 Conventional crude oil P NR 410 4100 Conventional crude oil P NR 42 Natural gas liquids (NGL) P NR 420 4200 Natural gas liquids (NGL) P NR 43 Refinery feedstocks S NR 430 4300 Refinery feedstocks S NR 44 Additives and oxygenates S NR 440 4400 Additives and oxygenates S NR 45 Other hydrocarbons

450 4500 Other hydrocarbons 46 Oil products S NR 461 4610 Refinery gas S NR 462 4620 Ethane S NR

180

463 4630 Liquefied petroleum gases (LPG) S NR 464 4640 Naphtha S NR 465 Gasolines S NR 4651 Aviation gasoline S NR 4652 Motor gasoline S NR 4653 Gasoline-type jet fuel S NR 466 Kerosenes S NR 4661 Kerosene-type jet fuel S NR 4669 Other kerosene S NR 467 Gas oil / diesel oil and Heavy gas oil S NR 4671 Gas oil / Diesel oil S NR 4672 Heavy gas oil S NR 468 4680 Fuel oil S NR 469 Other oil products S NR 4691 White spirit and special boiling point industrial spirits S NR 4692 Lubricants S NR 4693 Paraffin waxes S NR 4694 Petroleum coke S NR 4695 Bitumen S NR 4699 Other oil products n.e.c. S NR 5 Biofuels R 51 Solid biofuels R 511 Fuelwood, wood residues and by-products P R

5111 Wood pellets P R 5119 Other Fuelwood, wood residues and by-products P R 512 5120 Bagasse P R 513 5130 Animal waste P R 514 5140 Black liquor P R 515 5150 Other vegetal material and residues P R 516 5160 Charcoal S R 52 Liquid biofuels P R 521 5210 Biogasoline P R 522 5220 Biodiesels P R 523 5230 Bio jet kerosene P R 529 5290 Other liquid biofuels P R 53 Biogases P R 531 Biogases from anaerobic fermentation P R 5311 Landfill gas P R 5312 Sewage sludge gas P R 5319 Other biogases from anaerobic fermentation P R 532 5320 Biogases from thermal processes P R 6 Waste P 61 Industrial waste P NR 610 6100 Industrial waste P NR 62 Municipal waste P R/NR 620 6200 Municipal waste P R/NR 7 Electricity 70 Electricity 700 7000 Electricity 8 Heat 80 Heat 800 8000 Heat 9 Nuclear fuels and other fuels n.e.c. 91 Uranium and plutonium 910 Uranium and plutonium 9101 Uranium ores 9109 Other uranium and plutonium 92 Other nuclear fuels 920 9200 Other nuclear fuels 99 Other fuels n.e.c. 990 9900 Other fuels n.e.c.

181

Annex B. Additional tables on conversion factors, calorific values and measurement units

Table 1: Mass equivalents

INTO

FROM

Kilograms Metric tons Long tons Short tons Pounds

MULTIPLY BY

Kilograms 1.0 0.001 0.000984 0.001102 2.2046

Metric tons 1000. 1.0 0.984 1.1023 2204.6

Long tons 1016. 1.016 1.0 1.120 2240.0

Short tons 907.2 0.9072 0.893 1.0 2000.0

Pounds 0.454 0.000454 0.000446 0.0005 1.0

Example: Convert from metric tons (ton) into long tons: 1 ton= 0.984 long tons.

Table 2: Volume equivalents

INTO

FROM

U.S.

gallons Imperial gallons Barrels Cubic feet Litres

Cubic

metres

MULTIPLY BY

U.S. gallons 1.0 0.8327 0.02381 0.1337 3.785 0.0038

Imp. Gallons 1.201 1.0 0.02859 0.1605 4.546 0.0045

Barrels 42.0 34.97 1.0 5.615 159.0 0.159

Cubic feet 7.48 6.229 0.1781 1.0 28.3 0.0283

Litres 0.2642 0.220 0.0063 0.0353 1.0 0.001

Cubic metres 264.2 220.0 6.289 35.3147 1000.0 1.0

Example: Convert from barrels into cubic meters: 1 barrel = 0.159 cubic meter.

Table 3: Energy equivalents

INTO

FROM

TJ Million Btu GCal GWh ktoe ktce

MULTIPLY BY

Terajoule (TJ) 1 947.8 238.84 0.2777 2.388x10-2 3.411x10-2

Million Btu 1.0551x10-3 1 0.252 2.9307x10−4 2.52x10−5 3.6x10−5

GigaCalorie (GCal) 4.1868x10-3 3.968 1 1.163x10−3 10-4 1.429x10-4

Gigawatt hour (GWh) 3.6 3412 860 1 8.6x10-2 1.229x10-1

Ktoe 41.868 3.968x104 104 11.630 1 1.429

Ktce 29.308 2.778x104 0.7x10-4 8.14 0.7 1

Example: Convert from Gigawatt-hours (GWh) into Terajoules (TJ): 1 GWh = 3.6 TJ.

182

Table 4: Difference between net and gross calorific values for selected fuels

Fuel Percentage

Coke 0

Charcoal 0 – 4

Anthracite 2 – 3

Bituminous coals 3 – 5

Sub-Bituminous coals 5 – 7

Lignite 9 – 10

Crude oil 5 – 8

Petroleum products 3 – 9

Natural gas 9 – 10

Liquefied natural gas 7 – 10

Gasworks gas 8 – 10

Coke-oven gas 10 – 11

Bagasse (50% moisture content) 21 – 22

Fuelwood (10% moisture content) 11 – 12

(20% moisture content) 22 – 23



Sources: United Nations (1987).

Table 5: Influence of moisture on solid volume and weight of standard fuelwood

Percentage moisture content of fuelwood

100 80 60 40 20 15 12 10 0

Solid volume in m3

per ton 0.80 0.89 1.00 1.14 1.33 1.39 1.43 1.45 1.60

Weight in tons

per m3 1.25 1.12 1.00 0.88 0.75 0.72 0.70 0.69 0.63

Source: United Nations (1987).

Table 6: Fuelwood to charcoal conversion table

Influence of parent wood density on charcoal production

(Weight (kg) of charcoal produced per cubic metre fuelwood)

Coniferous

wood

Average tropical

Hardwoods

Preferred Tropical

hardwoods Mangrove (rhizophora)

Charcoal 115 170 180 285

Influence of wood moisture content on charcoal production

(Quantity of wood required to produce 1 ton of charcoal)

Moisture content (dry basis) 100 80 60 40 20 15 10

Volume of wood required

(cubic metres)

17.6 16.2 13.8 10.5 8.1 6.6 5.8

Weight of wood required (tons) 12.6 11.6 9.9 7.5 5.8 4.7 4.1


183

Table 7: Fuelwood requirement for charcoal production by kiln type

(Cubic metres of fuelwood per ton of charcoal)

Kiln Type Percentage moisture content of fuelwood

15 20 40 60 80 100

Earth kiln 10 13 16 21 24 27

Portable steel kiln 6 7 9 13 15 16

Brick kiln 6 6 7 10 11 12

Retort 4.5 4.5 5 7 8 9

Data are based on assumption of standard hardwood as input into the process.


Table 8: Energy values of selected animal and vegetal wastes

Wastes

Average moisture content:

dry basis

(percentage)

Approximate

ash content

(percentage)

Net calorific value

(MJ/kg)

Animal dung 15 23-27 13.6

Groundnut shells 3-10 4-14 16.7

Coffee husks 13 8-10 15.5-16.3

Bagasse 40-50 10-12 8.4-10.5

Cotton husks 5-10 3 16.7

Coconut husks 5-10 6 16.7

Rice hulls 9-11 15-20 13.8-15.1

Olives (pressed) 15-18 3 16.75

Oil-palm fibres 55 10 7.5-8.4

Oil-palm husks 55 5 7.5-8.4

Bagasse 30 10-12 12.6

Bagasse 50 10-12 8.4

Bark 15 1 11.3

Coffee husk, cherries 30 8-10 13.4

Coffee husk, cherries 60 8-10 6.7

Corncobs 15 1-2 19.3

Nut hulls 15 1-5 18.0

Rice straw & husk 15 15-20 13.4

Wheat straw & husk 15 8-9 19.1

Municipal garbage .. .. 19.7

Paper 5 1 17.6

Sawdust 50 1 11.7

Sources: United Nations (1987).

Note: Two dots (..) indicate that data are not available.

184

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Reference for GHG emissions:

186

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Documents

International Recommendations for Energy Statistics (IRES) · 2017. 10. 6. · Energy Statistics (IRES) United Nations. New York, 2016 [final edited version prior to typesetting]